Abstract: Circuitry for driving an LED array and a lamp including such circuitry. A fixed current source outputs a fixed current to an LED array. A variable load is provided in parallel to the LED array to also receive an output from the fixed current power supply. The variable load senses a condition affecting a luminous output of the LED array and varies an impedance based on this sensed condition. This variable load may typically include a thermistor or a photodetector. As the impedance of the variable load changes, current diverted from the LED to the variable load changes. Thereby, current supplied to the LED array, and thereby the intensity LED, can be controlled based on the impedance changing element in the variable load.

Abstract: An illumination device includes a cold cathode fluorescent tube having a heat capacity of 0.035 Wsec/.degree. C. or less per unit length (1 cm) of a glass tube of a fluorescent section of the cold cathode fluorescent tube. The illumination device has a superior operation characteristic at a low temperature. The device is driven by a method and is implemented in a display device.

Abstract: An electrodeless high intensity discharge lamp includes an electrodeless lamp capsule having an enclosed volume containing a mixture of starting gas and chemical dopant material excitable by high frequency power to a state of luminous emission, an applicator for coupling high frequency power to the lamp capsule, a gas nozzle directed toward the lamp capsule and a gas controller coupled to the gas nozzle. The gas controller receives gas from a gas source and supplies a gas puff of limited duration to the lamp capsule through the gas nozzle in response to termination of the state of luminous emission. The lamp capsule is rapidly cooled by the gas puff to a temperature required for restart.

Abstract: After the image data transmitted via a line is received and is then stored in a predetermined zone a of a RAM. The resolution of the image data along the line is converted to the resolution of the recording means in the main-scanning direction after the image data is decoded. The converted data is then stored in a predetermined zone b of the RAM. Subsequently, the image data is read by a predetermined length (eight pixels) to reverse the arrangement of the image data in the horizontal and vertical directions while converting the resolution of the image data to the resolution of the recording means in the sub-scanning direction. The resulting data is then stored in a predetermined zone c of the RAM.

Abstract: Operation of a vapor lamp light source for instrumentation utilizes a lamp manager controller for instant-on and precise temperature control to enhance and control output at specified wavelengths by monitoring and discriminating the spectral output of the lamp, and adjusting lamp current and temperature to maintain specific wavelength and light flux. Specific wavelengths can be selected and the wavelength automatically monitored for output level by control of a cold spot by an electrothermal device and a monitor. Lamp temperature, current and flux level at a selected wavelength are controlled.

Abstract: Disclosed is a control mechanism for regulating the temperature of a fluorescent lamp tube located within a housing. The control mechanism includes a cold spot mechanism defining the cold spot of the lamp tube, a heating mechanism, a power supply and a temperature sensor. The heating mechanism is connected to the power supply and is contiguous with a portion of the cold spot mechanism located outside of the housing. The temperature sensor is also coupled to the power supply and monitors the temperature of the cold spot mechanism. Based upon the temperature of the cold spot mechanism, the temperature sensor operates the power supply, so as to deliver power to the heating mechanism to warm the cold spot mechanism and maintain a cold spot temperature that allows the lamp tube to generate maximum visible light output.

Abstract: This invention relates to electrodeless fluorescent RF lamp which includes bulbous lamp envelope (10, 20) with a top, a bottom and a fill of rare gas and vaporizable amalgam (14) therein. A reentrant cavity (11, 21) is disposed adjacent the bottom of the envelope (10 a, 20a) and at least one tubulation (12, 22) extends from the envelope to hold at least a portion of the vaporizable amalgam. An induction coil (2) is disposed on lead wires and coupled with a radio frequency excitation generator for generation of a plasma to produce radiation. At least the major portion of the cold spot where the amalgam resides is maintained at a temperature between about 60.degree. and 140.degree. C. during operation of the lamp, by utilizing a portion of the induction coil to warm up to amalgam.

Abstract: A system for actively monitoring and controlling the effective ambient temperature in an application utilizing a fluorescent tube as the source of illumination. The system is the combination of a fluorescent tube, which may be thermally bonded to a reflector plate that is in physical contact with thermal electric cooler units and a heat sink. A temperature sensor in conjunction with drive circuitry and a power source, directs a magnitude and direction of current flow through the thermal electric cooler units thereby controlling the ambient operating temperature of the fluorescent tube.

Abstract: In some embodiments, a light bulb for an electrodeless discharge lamp has a protuberance such that the cold spot of the bulb is located in the protuberance. The protuberance is spaced from the induction coil of the lamp so as to be easily accessible. Hence the cold spot temperature is easy to measure and control. In some embodiments, heat sinks are provided to cool the light bulb. An active control element including a Peltier element is provided to control the cold spot temperature.

Abstract: An image formation apparatus comprises an image formation device for forming an image on a recording material according to image information light obtained from light emitted from a light source. A detector detects the light intensity emitted from the light source. A single cooling fan is provided for cooling both the light source and the image formation device. The drive force of the cooling fan is set at either a first value or a second value. The driving force is set at the first value during a time period from a start of energization of the light source until the light intensity detected by the detector is at least the predetermined value. The driving force is set at the second value after the detected light intensity is at least the predetermined value. The first value of the driving force is less than that of the second value.

Abstract: A lamp assembly includes a tubular incandescent lamp located between the four tube sections of a double twin tube compact fluorescent lamp such that heat is transferred from the incandescent lamp to the fluorescent lamp when the incandescent lamp is energized. A power source provides power to the incandescent lamp and to the fluorescent lamp through a thermal switch. The thermal switch is in thermal contact with the incandescent lamp and the fluorescent lamp. When the lamp assembly is turned on, the switch applies power to the incandescent lamp initially. When the switch is heated by the incandescent lamp to a predetermined temperature, the switch deenergizes the incandescent lamp and applies power to the fluorescent lamp.

Abstract: The mercury vapor pressure in a low pressure mercury discharge lamp is thermostatically controlled. A low pressure mercury discharge lamp includes electrodes and a source of mercury vapor sealed in a lamp envelope. A heater and a thermal switching device are in thermal contact with the source of mercury vapor. The heater is energized when the source of mercury vapor is below a predetermined temperature during operation of the lamp. The heater is preferably a resistance heater electrically connected in series with one of the lamp electrodes. The thermal switching device can be a bimetal thermostatic switch. The source of mercury vapor is typically an amalgam selected to have an optimum mercury vapor pressure at the maximum operating temperature of the lamp. The heater and the thermal switching device can be located external to the lamp envelope or can be located within the lamp envelope.

Abstract: A fluorescent lamp light output is maximized by cooling the cathode regions. Mercury vapor pressure is maintained at an optimum or desired level for light production by cooling the cathode areas of the lamp. The cooled cathode areas of the lamp collect cathode emissive material and mercury vapor condensates. Thus, the light output remains uniform and constant. The functional length of the lamp is not degraded by the deposition of either cathode material or mercury vapor condensates. Cooling can be effected by forcing cool air against the exterior of the lamp adjacent the cathodes or by using forced water heat exchangers. By cooling the respective cathode regions equally, the amount of deposition in the respective regions is substantially the same. Thus, gradations of deposition are avoided. The constant high output fluorescent lamp can be used with electronic inspection equipment and machine vision measurement devices.

Abstract: In a fluorescent lamp assembly for use in an image scanner, a heater is associated with a glass tube of a fluorescent lamp for heating the glass tube. A controller is provided for controlling the heater in such a manner as to maintain temperture of the glass tube at the predetermined optimum level at which a luminescent characteristic of the fluorescent lamp is stabilized.

Abstract: Dimming fluorescent lamp solid-state ballast. The ballast is adapted for automatic sensing and control of lamp temperature to dim the lamp to an optimal operating temperature, such as that at which the light output is a maximum per energy input. The ballast is also adapted for manual continuously adjustable or multi-position stepwise dimming control, which may include such an optimal setting. Other available dimming settings include undimmed or maximum light output, and/or the lamp's minimal sustainable light output.

Abstract: A plasma discharge apparatus has a first electrode, a counter electrode, and a power source for supplying power to the first and counter electrodes for initiating and sustaining plasma discharge therebetween. An isolated heater is provided for heating only the first electrode. An isolated temperature sensor is provided for sensing the temperature of the first electrode, and a temperature controller is provided, responsive to the output of the temperature sensor, for controlling the heater to control the temperature of the first electrode.

Abstract: A spark gap switch system is disclosed which is capable of operating at a high pulse rate comprising an insulated switch housing having a purging gas entrance port and a gas exit port, a pair of spaced apart electrodes each having one end thereof within the housing and defining a spark gap therebetween, an easily condensable and preferably low molecular weight insulating gas flowing through the switch housing from the housing, a heat exchanger/condenser for condensing the insulating gas after it exits from the housing, a pump for recirculating the condensed insulating gas as a liquid back to the housing, and a heater exchanger/evaporator to vaporize at least a portion of the condensed insulating gas back into a vapor prior to flowing the insulating gas back into the housing.

Abstract: A spark channel purge system for high pulse repetition frequency spark gap switches. A purge fluid having a liquid state and a gaseous state is caused to flow through a spark gap channel, at least a portion of the purge fluid passing through the spark channel being in the gaseous state. The purge fluid is supplied in its liquid state by a purge fluid source. In some embodiments, the purge fluid source is a recirculating flow loop which includes a heat exchanger, while in another embodiment, the purge fluid source is a low-pressure liquid storage vessel. The heat exchanger transfers waste heat from the spark gap switch via the purge fluid flowing from the spark channel into the purge fluid supplied by the purge fluid source. This causes at least a portion of the liquid purge fluid to change to the gaseous state. In some embodiments, the spark channel purge system is suitable for a closed loop system, while other embodiments are suitable for an open loop system.

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: A fluorescent lamp device which is used for backlighting of a liquid crystal display and in which a Peltier element is thermally coupled with a portion of a fluorescent lamp and a temperature sensor is provided at that portion to be cooled. In accordance with the temperature of the cooled portion detected by the temperature sensor the driving of the Peltier element is controlled so that the temperature of the cooled portion is reduced under a predetermined temperature.

Abstract: A highly stable high intensity atomic emission light source has a discharge region and the sample region each controlled by a separate heater. The sample region heater is controlled by a lamp stabilizer circuit which maintains the breakdown voltage within the discharge region at a constant level, thus providing a stable and high intensity light source.

Abstract: An overtemperature protector for an incandescent lamp socket housing comprises a glass enclosed circuit breaker and an electrical heater in proximate heat transfer relationship therewith. The heater is in series with the circuit breaker so that when the circuit breaker is open, there can be no current flow through the heater.

Abstract: In an operating apparatus of a high-pressure discharge lamp of the invention, power is supplied to a heater provided in a high-pressure discharge lamp from a battery. The battery is charged by a charger which is driven by a power section. The power section is started by an ON operation of a switch which is turned on/off synchronously with the operation of a control switch. The control switch allows power supply from the battery to the heater when it is turned on. Therefore, always while power is supplied to the heater, the battery is being charged by the charger so that the voltage of the battery will not be lowered.

Abstract: An alkali metal vapor discharge lamp is operable in a pulsed mode. The vapor discharge lamp includes an inner envelope made of first ceramics and an outer envelope made of second ceramics for enclosing the inner envelope under a vacuum atmosphere or an innert atmosphere. The inner envelope contains cesium, mercury and a rare gas, the vapor pressure of which cesium is selected from 400 to 1000 Torr. The second ceramics of the outer envelope is selected to be alumina ceramics.

Abstract: An overtemperature protector for an incandescent lamp socket housing comprises a glass enclosed circuit breaker and an electrical heater in proximate heat transfer relationship therewith. The heater is in series with the circuit breaker so that when the circuit breaker is open, there can be no current flow through the heater.

Abstract: An electron emission device for attracting electrons emitted from an electron emission element to an anode, includes a current detector for detecting a flow-in current to said electron emission element and a flow-out current from the electron emission element. The difference between the flow-in current and the flow-out current is calculated and the voltage applied to the electron emission element is adjusted in accordance with the difference between the flow-in current and the flow-out cuttent.

Abstract: To provide for preheating of a high-pressure discharge lamp (6) having a charge vessel (7) closed off by a pinch or press seal (8), a ceramic holder (1), typically a ceramic tube with multiple capillary openings therein, has a heating wire threaded through the capillary openings, and the ceramic holder is located in intimate thermal transfer with respect to the lamp, for example by being placed and cemented in the transition zone between the discharge vessel (7) and the pinch or press seal. Heater power of about 10 W applied to two such ceramic capillary heaters located adjacent both sides of the pinch or press seal permits preheating the fill of the lamp so that 40% of rated light output can be obtained within several seconds after energization of the electrodes. The lamp is suitable as a headlamp for vehicular use and can be constructed in miniature size, with a discharge vessel volume in the range of 100ths cm.sup.3.

Abstract: A discharge tube adapted to produce a light by an extraneous high frequency electromagnetic field is heated before discharge to thereby improve the rising-up of the discharge and achieve uniformization of emitted light. Further, the discharge tube is heated by an electrode which applies a high frequency electromagnetic field to the discharge tube.

Abstract: An illumination apparatus includes a discharge tube for emitting light upon an application of an external high frequency wave electromagnetic field, an electrode, arranged outside the discharge tube, for applying the high frequency wave electromagnetic field to the discharge tube, a high frequency wave applying unit for supplying high frequency wave power to the electrode, and a projected portion extending from the discharge tube. The projected portion extends to a position where the high frequency wave electromagnetic field generated by the electrode has a level lower than a discharge initiation level. The high frequency wave power is controlled by changing a voltage, a frequency, a duty ratio or the like.

Abstract: A microchannel plate with a plurality of microchannel portions, a portion in an amplifying direction from another portion having a lower surface zone resistance than the other, materials and circuitry being provided to permit controlled higher-temperature operation.

Abstract: Apparatus and method for automatic control of with a high pressure mercury arc lamp is described. The apparatus includes a control unit that monitors the current and the voltage supplied to the arc lamp. A temperature measuring device is coupled to a portion of the lamp for monitoring the temperature. The control device controls a flow of air past the lamp by controlling the power to a fan motor or by controlling the flow of air by controllable dampers. After equilibrium conditions are established, the control unit determines and stores the equilibrium values of current and voltage. Thereafter the control unit monitors the values of current and voltage periodically. When these measured voltage and current values are outside of predetermined limits, the control unit initiates shut down operation of the lamp.

Abstract: In a discharge tube lighting system for use in a vehicle, a heat generating element, which is made of metal material, is formed on an outer surface of a tube element of the discharge tube along the longitudinal direction of the tube element, and a temperature detecting element is provided on a surface of the heat generating element. The heat generating element is electrically driven to heat the discharge tube at a starting period of lighting the discharge tube when a temperature of the heat generating element detected by the temperature detecting element is lower than a predetermined temperature. The heat generating element is formed in a rectangular shape and conformally disposed on a portion of the tube. The heater element has first and second ends which are disposed with respect to the electrodes of the tube to cause an electric field to be provided between each electrode and the corresponding end of the heater element.

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: 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: The temperature of a fluorescent lamp is optimized by monitoring the current used to power the lamp and changing the cooling state (on to off, off to on) whenever lamp current increases. The optimum current level is some minimum value; any increases in this value are detected and a signal is fed back to a controller which regulates the instant mode of operation of a cooling device. With the cooling mode reversed, the lamp current will be reduced towards its optimum value. The cooling mode remains unaltered until the lamp current rises again. Thus the optimum temperature (minimum current to produce the required light level) is achieved without reference to either an absolute current or temperature.

Abstract: A high intensity discharge ballast that provides instant restrike of hot high intensity lamps, rapid warm-up and normal ballasting functions so as to circumvent the deficiencies of heating and cooling cycles in high intensity discharge lamps which cycles are unacceptable in special applications such as graphic arts and stadium lighting.

Abstract: When a display incorporating electroluminescent (EL) device is switched on, the electrical resistance across electrodes and which indicates the moisture content of the EL layer is measured by electrical resistance measuring device. If the resistance is below a preset value corresponding to an unacceptable moisture content a current pulse source is activated to heat the EL layer and evaporate the moisture. The resistance is also measured periodically during continued use of the display.

Abstract: An improved high pressure sodium vapor lamp is described having resistance heater means contained within a tubular light-transmitting ceramic envelope that further contains a reservoir of sodium-mercury amalgam in excess of the quantity vaporized during lamp operation in order to heat the ceramic envelope before lamp starting and thereby reduce the starting voltage requirements. In the preferred embodiment, said resistance heater means comprises a refractory metal coil wound around the tungsten shank of one thermionic electrode and electrically insulated therefrom and which is supplied with lower current than is subsequently applied to said electrodes for the lamp operation.

Abstract: To prolong the life of a deuterium gas discharge lamp and reduce photometric noise, a DC potential is applied between the cathode and the anode of the lamp to support the arc current through the tube and a separate AC potential is connected across the cathode through an AC amplitude control circuit that controls the amplitude of the AC current. While the cathode is at room temperature, a potential proportional to the AC current through the cathode is balanced against a potential proportional to the AC potential drop across the cathode in an operational amplifier circuit and the output used to operate an indicating device. During operation of the lamp, the output of the operational amplifier circuit is used to control power applied to the cathode through the AC amplitude control circuit.

Abstract: A feedback control system for maintaining the intensity and spectral distribution of light at a predetermined level at a wavelength characteristic of the excited source. Control of that intensity, which exhibits a systematic but not necessarily a monotonic relation with excitation, is achieved by measuring and controlling the intensity of flux at another characteristic wavelength which is both systematic and monotonic.

Abstract: A control circuit is provided in projection apparatus to control the operating characteristics of the projection lamp. The projection lamp control circuit maintains a constant illumination output and color temperature of the projection lamp to provide improved operation and increased lamp operating life. The desired operating point of the projection lamp is accurately maintained by sensing the operating point of the projection lamp and utilizing the sensed deviation from the desired operating point to vary the output of a blower that provides cooling of the lamp. Thus, the operating point and color temperature of the projection lamp is accurately maintained in a closed loop arrangement by sensing the operating point of the lamp and controlling the blower output.

Abstract: An HID lamp utilizes a thin, fragile, strip-like conductor member affixed to and carried on a portion of the inner surface of the lamp protective envelope. Upon breakage of the protective envelope, the fragile conductor will break and interrupt the electrical continuity of the lamp's electrical circuit, thereby rendering the lamp inoperative.

Abstract: A method for varying the voltage in a high intensity discharge mercury lamp comprising the following steps:(a) energizing the lamp at a substantially fixed current;(b) selecting a predetermined voltage;(c) sensing the lamp voltage; and(d) when the lamp voltage rises above the predetermined voltage, directing a pulsed flow of gas, which gas is at a temperature sufficient to condense the mercury, against the outer surface of the lamp intermediate of its electrodes at a pulse rate and pulse duration sufficient to achieve and maintain about the predetermined voltage.

Abstract: A low pressure metal or metal halide vapor lamp for photocopying applications. The low pressure sodium vapor lamp is operated in a continuous mode and provides illumination of increased brightness and of a color (yellow) which is optimum for providing a copy which is an accurate representation of the original. An auxiliary heater is formed on the lamp to both decrease the warm-up time of the lamp and to control lamp temperature for optimum light output, an electrical control circuit being coupled to the heater to control the current therethrough.

Abstract: A discharge lamp has an electrically conducting transparent layer and a temperature control which responds to variations of the lamp current to control lamp temperature. A control member causes an auxiliary current to flow intermittently through the said layer. The temperature control is adjusted so that in the operational condition the lamp will always be operating in a voltage-current range having a positive nature. As a result, the lamp does not require an electric stabilizing ballast.