Abstract: A stroboscopic controller for illuminating a photographed object by discharging a charge stored to a main capacitor through a light emitting tube has a voltage measuring device for measuring a charging voltage of the main capacitor before light emission; a light quantity calculator for calculating a quantity of light required to illuminate the photographed object; a voltage calculator for calculating a voltage of the main capacitor at a stopping time of the light emission from the charging voltage measured by the voltage measuring device and the quantity of light calculated by the light quantity calculator; a time calculator for calculating a stroboscopic light emitting time for which the voltage of the main capacitor is changed by the stroboscopic light emission from the charging voltage before the light emission to the voltage at the stopping time of the light emission; and a light emission control device for controlling a light emitting operation and a stopping operation thereof with respect to the light e

Abstract: A method and apparatus for measuring and adjusting output of a heat lamp for an optical TLD reader includes an optical system which matches the optical system of the TLD reader, means for supporting a heat lamp to be calibrated, and an element plate having at least one heat absorbing substrate supported in alignment with the optical system. The heat lamp is electrically connected to a lamp driver circuit of the TLD reader, and a thermocouple is mounted in thermal contact with the heat absorbing substrate. In use, the lamp driver circuit of the TLD reader drives the heat lamp mounted in the calibration and adjusting device. This device monitors the signal generated by the thermocouple and displays this signal as a measured heat response curve. This measured heat response curve can be compared with a `standard` or reference heat response curve to determine whether the lamp driver circuit has been adjusted properly for the heat lamp being tested, and to determine the nature of any required adjustments.

Abstract: A driver circuit for an electroluminescent lamp has a photo-diode for detecting the light intensity of the electroluminescent lamp and providing an output signal responsive to the intensity of the lamp and a circuit responsive to the output signal for driving the electroluminescent lamp at a set intensity.

Abstract: A circuit for starting and operating a gas discharge lamp (11) comprises: a DC power supply (73), which generates a DC power supply voltage; a high voltage generator (16, 18), which generates a high DC starting voltage from the DC power supply voltage and supplies the high DC starting voltage to the gas discharge lamp (11) so as to bring about a current flow therethrough; and inductor (15), which is connected in a closed loop circuit together withthe gas discharge lamp (11); a sensor (48), which is connected to the closed loop circuit for detecting the transmission of power therein; and a power switching (59, 60), which is switchable between a conducting state in which power is induced into the inductor (15) and a non-conducting state in which no power is induced into the inductor (15), and which is controlled by the sensor (48).

Abstract: The lamp has a holder body in which an end portion of the discharge vessel is secured. A light-receiving window of a photoelectrical element is positioned inside the holder body and aimed at a sealed end portion of the discharge vessel. The photoelectrical element may be connected to the control of the electric supply of the lamp in order to obtain a high luminous flux within a short period after ignition of the lamp. External factors have little influence on the control action thanks to the position of the window.

Abstract: A solid state power supply and light emission controller for a luminescent lamp which converts alternating current line voltage, or direct current voltage, into a constant repetition rate, variable width pulse alternating current voltage for energizing the lamp and for controlling the light emission of the lamp. The power supply provides essentially constant contrast (light brightness ratio) in the light emission from the lamp in the presence of variations in ambient light level. The system achieves its desired result by sensing the ambient light level and also by sensing the level of the light emitted by the lamp. The luminescent lamp may, for example, be a neon lamp, a white light fluorescent lamp, an incandescent lamp, or the like.

Abstract: An arrangement for compensating against changes in parameters of an optical emitter and an optical receiver in an optical scanner that detects different luminosities. The optical receiver is exposed to light from the optical emitter and provides an output voltage that is compared with a reference voltage. The output voltage is clamped to the reference voltage when the light received by the optical receiver has energy of an extreme value. The receiver detects light of varying brightness between maximum brightness and minimum brightness, and will operate at any durations of varied brightness levels. The receiver distinguishes between maximum brightness and minimum brightness, and when the brightness has a step-shape, a stair-shape function is provided by the receiver output voltage. The output voltage of the receiver is clamped to the reference voltage when the light energy received by the optical receiver attains either a maximum or a minimum.

Abstract: An inverter is powered by a magnitude-modulated DC supply voltage derived by rectification from an ordinary 120Volt/60Hz electric utility power line. The inverter powers a low voltage (12 Volt) incandescent lamp with a magnitude-modulated high frequency (30 kHz) voltage. The magnitude modulation on the high frequency voltage is proportional to the magnitude modulation on the DC supply voltage.

Abstract: A lighting system having at least two independent lighting subsystems each with a different ratio of scotopic illumination to photopic illumination. The radiant energy in the visible region of the spectrum of the lighting subsystems can be adjusted relative to each other so that the total scotopic illumination of the combined system and the total photopic illumination of the combined system can be varied independently. The dilation or contraction of the pupil of an eye is controlled by the level of scotopic illumination and because the scotopic and photopic illumination can be separately controlled, the system allows the pupil size to be varied independently of the level of photopic illumination. Hence, the vision process can be improved for a given level of photopic illumination.

Abstract: An automatic battery powered video light (10) is supplied power by a d.c. battery (16). A light (20) is connected between a first terminal of the battery (16) and a MOSFET switch (46), which is connected to a second terminal of the battery (16). A control circuit (24) controls the opening and closing of the MOSFET (46) to supply power to the light (20) and disconnect power from the light (20). The control circuit (24) includes a light sensor (36) for sensing ambient light and reflected radiant light from a scene (14) and a pulse modulator (40) for controlling the MOSFET switch (46). The modulator (40) adjusts pulse frequency and therefore closing time of the switch (46) when the sensor (36) senses time low light levels, and vice versa. Also provided is a dual filament light (20') wherein each filament (52, 54) is independently controlled to enhance color balance.

Abstract: Sensor system for regulating machines, especially sewing machines, with a light barrier comprising a light emitter and a light receiver. The light emitter provided is an incandescent lamp supplied from an energy source. An evaluating stage of adjustable sensitivity is connected to the light receiver. The energy source of the incandescent lamp is regulated, and is coupled with the evaluating stage in such a way that the desired value of the regulated energy source is automatically adjustable in dependence on the sensitivity setting of the evaluating stage.

Abstract: A color measuring apparatus for measuring the color of a sample has a light source measuring section for detecting color temperature of light coming from a light source without passing through or being reflected by the sample. Relationship between a plurality of color temperatures and a plurality of emission time periods of the light source is stored in a memory. A microcomputer compares each of detected color temperatures with a predetermined value and determines a certain time period on the basis of both the relationship stored in the memory and a comparison result. A lighting circuit energizes the light source during the time period determined by the computer so that the light source keeps lighting the sample. A sample measuring section detects light coming from the sample and the microcomputer measures a color of the sample.

Abstract: A fluorescent X-ray viewer includes a photosensor within the housing proximate to the fluorescent lamps for detecting the intensity of the light prior to transmission through the X-rays or other transparencies to be viewed. A dimming circuit is used to adjust the intensity of the fluorescent lamps to less than the nominal value, and feedback through the photosensor is used to maintain the light intensity output at a substantially uniform level to compensate for line and load variations and aging and changes of the efficiency of the fluorescent lamps. The X-ray viewer is provided with an LED warning indicator which is energized when the lamps have deteriorated to an extent which requires replacement.

Abstract: An LED stabilizing light source device comprises an LED, a drive circuit for driving the LED, a wavelength filter for filtering the light emitted from the LED, a light splitter for splitting the light passing through the filter, a photodiode for receiving the split light. The device further comprises a feedback loop for feeding an output of the photodiode to the drive circuit.

Abstract: An auto-flash photographing system includes a flash lamp unit, a photometry unit for detecting light reflecting from a subject of interest, a reference setting unit, a comparator, and a trigger unit. The flash lamp is once triggered to emit a flash, and the light detected by the photometry unit is compared with a reference value defined by the reference setting unit by the comparator. If the detected light is lower than the reference value, it indicates underexposure so that the trigger unit once again triggers the flash lamp. In this manner, the flash lamp is fired more than once while a shutter is set in a fully open condition until an optimal exposure condition is attained. In another structure, a plurality of flash lamps are provided they may be fired at the same time and extinguished separately or they may fired one after another in sequence until a desired exposure condition for phototaking is obtained.

Abstract: A stable fiber optic light source is produced by a supply circuit comprising a current-producing power source 10, a comparing means 20, phase shifter 30, transistor circuit 40, light-emitting diode 50, and a feedback control system. The feedback control system comprises a mixing rod 103 for conveyance of the optical power, a splitter 16 for receiving the optical power from the mixing rod 103 and for splitting the power into fiber optic product portions 62 and 63, and a fiber optic control portion 64 and a detector 70 for sensing the optical power from the fiber optic control portion 64 and for producing, in response thereto, an electrical control signal 105 for control of the power circuit 10.

Abstract: The present invention is directed to an illumination source (10) for illuminating an object (11) with light (16) of substantially constant intensity. The illumination source includes an electric light bulb (12) which is supplied with voltage from an adjustable- voltage power supply (14). The voltage supplied by the power supply (14) varies in accordance with the intensity of the light (16) radiated from the bulb (12), as sensed by a photodiode (24). The photodiode (24) is separated from the bulb by a length of lightguide fiber (26) into which light from the bulb is coupled by a glass rod (28). The fiber (26) and the rod (28) allow the photodiode (24) to be supplied with light from the bulb (12), yet to be thermally insulated therefrom, so as to avoid thermal run-away of the diode.

Abstract: An electrodeless lamp system and method for providing light output having a controlled spectral distribution. A lamp having a fill which is not fully vaporized at the lamp operating temperature and which emits in a characteristic region of the spectrum is used. A function generator generates a function signal, and the magnitude of the lamp output in the characteristic region or the ratio of such magnitude and a magnitude in a different characteristic region is compared with the function signal. The difference signal is used to control the amount of cooling gas which is incident on the lamp bulb to control the spectral distribution of the radiation which is emitted by the lamp.

Abstract: An automatic battery powered video light (10) is supplied power by a d.c. battery (16). A light (20) is connected between a first terminal of the battery (16) and a MOSFET switch (46), which is connected to a second terminal of the battery (16). A control circuit (24) controls the opening and closing of the MOSFET (46) to supply power to the light (20) and disconnect power from the light (20). The control circuit (24) includes a light sensor (36) for sensing ambient light and reflected radiant light from a scene (14) and a pulse width modulator (40) for controlling the MOSFET switch (46). The modulator (40) increases pulse width and therefore closing time of the switch (46) when the sensor (36) senses time low light levels, and vice versa. Also provided is a dual filament light (20') wherein each filament (52, 54) is independently controlled to enhance color balance.

Abstract: A light emission controlling device for an electronic flash apparatus includes a first photometric unit for metering a first region of an object field in a weighted manner and outputting first photometric informaiton with a lapse of time; a second photometric unit for metering a second region of the object field in a weighted manner and outputting second photometric information with a lapse of time; a comparing unit for comparing the first photometric information with the second photometric information; and a controlling unit for determining timing for outputting a light emission stop signal on the basis of the relationships between the first photometric information and the second photometric information.

Abstract: An apparatus detects the degree of crowding in an elevator hall utilizing a television camera to provide video signals which are stored as video data and including an illumination controller which controls the brightness of an illuminator for the elevator hall when the difference between reference data and video data has exceeded a predetermined value and has continued for a predetermined time, so that the difference between the reference data and the video data may fall within the predetermined value.

Abstract: A source of illumination of constant color temperature and intensity including a lamp the color temperature of the light from which is dependent on the power applied to the lamp. There is a device for measuring the intensity of portions of the spectrum of the light and for providing signals indicative of those intensities. Means responsive to the signals adjust the power to achieve the selected color temperature. A light modulator adjusts the intensity without affecting color temperature. There is a spherical mirror centered on the lamp and the modulator is located between the lamp and the mirror and controls the brightness of the image of the lamp formed on the lamp by the spherical mirror.

Abstract: A dual-filament light bulb with associated adapter apparatus which uses photovoltaic cells mounted within the light bulb to charge a battery which powers one of the filaments. The adapter apparatus is designed to mount in an ordinary light socket which provides external current to the other filament. The adapter apparatus includes circuitry which alternately switches from the filament powered by the battery to the filament powered by external current in a manner which reduces the amount of electricity needed to produce a given amount of light.

Abstract: In a flash photographing apparatus, a flash device is arranged to slow the rise of flashing characteristic thereof at the initial stage of flashing. To attain this purpose, the electric charge of a first capacitor is impressed via an inductance onto a flash tube at the initial stage of flashing. Following this, the electric charge of a second capacitor is directly impressed on the flash tube without passing through the inductance.

Abstract: An electronic ballast powers fluorescent lamps in a lighting fixture with a current of magnitude related to the frequency of the ballast output voltage. The ballast comprises self-oscillating inverter means wherein the frequency of oscillation can be influenced by receipt of a control signal at a control input connected in circuit with the inverter's positive feedback circuit. The ballast also comprises optical sensor means so positioned and constituted as to sense the light level within the lighting fixture and to provide a control signal commensurate with the light level. This control signal is then applied to the control input in such manner as to regulate the inverter frequency as a function of the light level, thereby correspondingly to regulate the magnitude of the current fed to the fluorescent lamps.

Abstract: Disclosed is an apparatus for stabilizing the light output of a high pressure discharge lamp comprising a coil generating a magnetic field acting upon the arc of the high pressure discharge lamp, an arc position detector detecting deviation of the position of the arc, and a magnetic field control circuit controlling the coil in response to the deviation detection output signal of the the arc position detector thereby setting right the position of the arc of the high pressure discharge lamp.

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: Electronic flash equipment in the present including a Field Effect Transistor which is connected to a flash tube in series and a voltage control structure which controls the conductivity of the Field Effect Transistor by control of a voltage across the gate and the source of the Field Effect Transistor. A automatic light control and a high frequency repeating flash light radiation are realized by control of the voltage.

Abstract: A control circuit for a photoflash gun capable of fast recycling times, including a flashtube (FT), a switching circuit (SW, L1) for initiating operation of the flashtube, a switch (CR1) in series with the flashtube and switched on at the same time as the flashtube to permit current flow through it, and an arrangement for resetting the switch (CR1) after a predetermined time to cut off current flow through the flashtube. The arrangement comprises an inductance (L2) and a capacitor (C2) coupled to the anode of the switch (CR1), so that when the flashtube is switched on, current discharges through the capacitor (C2), creating a back EMF in the inductance (L2). A voltage of negative polarity is thus developed across capacitor (C2) to switch off switch (CR1) after a predetermined time, thereby to switch off the flashtube. The switch off time is controlled by a light calculation circuit responsive to ambient light.

Abstract: A lamp illumination adjusting apparatus for automobiles comprises a reference triangular wave generator, an adjusting voltage setting circuit, a comparator to compare the reference triangular signal with the adjusting voltage and to output comparison signal, a driver circuit including a MOS field effect transistor which is controlled directly by the comparison signal, and a lamp which is connected in series to the driver circuit and interposed between a power source terminal and the ground.

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: A light sensing compensation system is provided for controlling the level of light at a workplane so that the ratio of the light at the ceiling where the sensor means is located to the level of controlled light at the workplane is maintained substantially constant as daylight entering the room varies.

Abstract: A room lighting control system which controls the electrical power supplied to the artificial lighting in an area based on the ambient light available. A photocell controlled digital lamp dimming circuit with particularly high stability for time and temperature is combined with a slow response time to avoid short term adjustments. A digital counter is used to determine a large number of steps over the adjustment range and the driving clock operates at a very low frequency, so that changes in light level take a relatively long time, and it takes an exceptionally long time to span the entire adjustment range.

Abstract: A lighting intensity control device that controls light intensity in a manuscript reproduction apparatus includes a back plate which has a manuscript area on which a manuscript can be disposed and a monitor area outside the manuscript area; a source of light which illuminates the manuscript and the monitor area of the back plate; a photodetector arranged so as to detect the brightness of the light reflected by the manuscript and by the monitor area of the back plate; and a light control element which controls the lighting time of the source of light during each scan period so as to keep the brightness of the light reflected by the monitor area of the back plate within a predetermined range.

Abstract: The invention comprises a self-adjusting ballast system for a high intensity discharge lamp. The ballast has a current limiter which modifies the lamp's present duty cycle to prevent damage if bulb rectification or another overcurrent condition occurs. It also has a current integration feedback loop for controlling lamp current during start-up.

Abstract: A self-adjusting ballast system for a high intensity discharge lamp. A lightweight, inexpensive and efficient ballast controls the strike and warmup stages of the high intensity discharge lamp, in particular high wattage lamps, through direct sensing of the radiant energy or heat output of the lamp itself. A current controller corrects for current imbalance in the alternating current lamp circuit due to bulb rectification or magnetic imbalance in the inverter transformer system.

Abstract: In an electronic flash apparatus which is provided with a first discharge tube for bounce illumination and a second flash discharge tube for direct illumination, emission of flash light by the first flash discharge tube and emission of flash light by the second are arranged to separately begin and to simultaneously end to simplify complex circuit arrangement otherwise required for having the amount of light reflected by the object of flash light emission by the first discharge tube and that of flash light emission by the second discharge tube in a fixed ratio. The second discharge tube is arranged to flash without fail despite of the simplified circuit arrangement.

Abstract: A strobe light firing circuit is provided with an integrated circuit (10) for deriving both timing and power generating pulses. A field-effect power transistor (16) gates the power generation transients while effectively isolating the timing integrated circuit (10) from high transients during the switching of the transistor (16). Timing pulses from the timing circuit (10) are divided in frequency by a binary counter (38) and then sequentially applied at the output pins of a decade counter (40) for strobe timing sequence selection. A strobe light firing pulse is differentiated (48) to form a pulse for shutting off power generation pulses from time (10) for a time effective for the flash tube (58) to recover for a subsequent discharge.

Abstract: The present invention provides a photographic lighting apparatus for illuminating a photographic object in taking the object with a camera such as a television camera or an 8 mm movie camera. The photographic lighting apparatus is capable of illuminating the object practically at a fixed intensity of illumination regardless of the variation of the distance between the object and the lamp thereof by reducing the brightness of the lamp when the object is located near to the lamp and increasing the same when the object is located remotely. The brightness of the lamp is regulated by controlling the conduction angle of a thyristor connected to the lamp according to the output signal of a photometric circuit which measures the intensity of illumination of the object.

Abstract: An electronic flash of series controlled type is provided. It comprises a series connection of a flash discharge tube and a main thyristor, which series connection is further connected in series with a thyristor which forms a reverse charging path for a commutating capacitor. The series combination of the flash discharge tube, the main thyristor and the last mentioned thyristor is connected in parallel with a main capacitor. A diode is connected in series with the commutating capacitor so that their series combination is in parallel with the reverse charging thyristor. The reverse charging thyristor is rendered conductive as the main thyristor is rendered conductive so as to establish a reverse charging path for the commutating capacitor therethrough when a commutating operation is to be performed. This prevents a reverse charging current to the commutating capacitor from passing through the flash discharge tube, thus enabling an accurate control over the amount of exposure produced by flashlight.

Abstract: An electronic flash device fires one or a pair of flash tubes sequentially for continuous shooting photography with a motor driven photographic camera, for substantially continuous illumination or for sequential illuminations at intervals, as well as fire the flash tube a single time for one shot photography. The flash device is provided with a main capacitor and an auxiliary capacitor which selectively energize the flash tube or tubes. The auxiliary capacitor is charged by the main capacitor and discharged to energize the flash tube for a small amount of flash light and shorttime restoration of the flash firing circuit. When a pair of flash tubes are employed, they are alternatively actuated for the sequential firing and one of them is actuated for the single time firing. The pair of flash tubes are coupled with each other through a commutation capacitor and switch elements for quick repetition of their firings.

Abstract: An indoor lamp and electronic circuit unit that may function in either an automatic mode or operate as any other normal lamp with manual control. When operated in the automatic mode the said lamp unit will turn on in response to a predetermined local ambient light level. The light level is detected and processed via a photo-transistor and electronic circuitry. Once the said lamp units light turns on the light will then remain on regardless of the light level detected by the said photo-transistor for a specified period of time. After this time has ellapsed the lamp unit will turn off. The process may begin over if the local ambient light level is again below the predetermined level. When operated in a normal or manual control mode the said lamp unit will turn on or off only in response to manually operating the lamp units switch.

Abstract: A protective device for a plurality of electrical circuits includes a pluity of isolated electrodes forming a gap with a common electrode. An output signal, electrically isolated from the circuits being monitored, is obtained by a photosensor viewing the discharge gap through an optical window. Radioactive stabilization of discharge characteristics is provided for slowly changing voltages and carbon tipped dynamic starters provide desirable discharge characteristics for rapidly varying voltages. A hydrogen permeation barrier is provided on external surfaces of the device.

Abstract: The light output of a fluorescent lamp is controlled and optimized. The light output of a lamp peaks at some optimum value of mercury cold spot temperature. During operation the lamp output is continually monitored, any drop in peak light output is detected, and a signal is generated which reverses the instant mode of operation of a cooling device placed in proximity to the lamp cold spot. With the cooling mode reversed, the light output will rise towards the peak. The cooling mode remains unaltered until the light output falls again.

Abstract: The light output of a fluorescent lamp is controlled and optimized. Both the light output and the lamp voltage peak at nearly the same value of mercury cold spot temperature. Controlling the lamp voltage therefore controls the light output. Thus, when the lamp voltage is continually monitored, any decline from the peak voltage is detected and a signal is generated which reverses the instant mode of operation of a cooling device placed in proximity to the lamp cold spot. With the cooling mode reversed, the lamp voltage will rise towards the peak. The cooling mode remains unaltered until the lamp voltage falls again.

Abstract: A control circuit for timing the duration of a flash of artificial illumination from an electronic flash maintains a substantially uniform amount of artificial illumination regardless of the ambient scene light intensity by detecting the ambient scene light intensity up to the instant that the flash is fired and thereafter subtracting the ambient scene light intensity so detected immediately prior to the flash being fired from the ambient and artificial scene light intensity detected during the flash of artificial illumination.

Abstract: The phosphor light output of a fluorescent lamp is controlled and optimized. The phosphor light output of the lamp corresponds to a particular level of either the vapor mercury or rare fill gas contained within the lamp envelope. This gas emission level is initially determined for a given system; a monitoring circuit thereafter detects any deviation from this level, generates a signal and sends it to a controller. The controller adjusts the operation of a mercury cold spot temperature-regulating device causing the cold spot temperature to increase or decrease until the optimum temperature and hence lamp phosphor light output is reestablished.

Abstract: An indicator for proper or improper exposure provided by automatic electronic flash includes a first decision circuit having a first decision level lower than a proper level of exposure, and a second decision circuit having a second decision level higher than the proper level of exposure. Thus, a given film latitude is allowed for the overexposure and the underexposure in determining and displaying the overexposure, the underexposure or proper exposure.

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: The disclosure is directed to an improved light measuring device which is used in flash photography for measuring a preliminary flash light to obtain camera exposure informations for photography under a primary flash light. The device is so arranged as to preliminarily obtain information of light amount contributing to photographing, with respect to each portion or area of a scene to be photographed or object field, in taking photographs with the employment of the auxiliary light.