Abstract: A driving device of a light source includes an arc sensing unit and an inverter. The light source includes a lamp having a first terminal and a second terminal. The arc sensing unit extracts a high frequency component from a voltage applied to the light source and generates an arc sensing signal in response to the high frequency component. The inverter controls the light source in response to the sensing signal.

Abstract: A method and apparatus for detecting a zero crossing or desired phase angle of a power line signal having a variable amplitude uses a ratio between a peak amplitude of the power line signal and the amplitude of the power line signal at a desired phase angle for a known amplitude version of the power line signal to detect when a variable amplitude version of the power line signal is at the desired phase angle or zero crossing. The detection of the phase angle is used to determine if a notch is present in the power line signal. A substantially constant width pulse is generated if a notch is detected regardless of the amplitude of the power line voltage or current. The invention is particularly useful in a lighting system for generating and detecting pulses used to communicate information from a power line communication controller to a series of electronic ballasts over a power line used to power the ballasts. The information can be used to control a dimming function of the ballasts.

Abstract: A controller 5 for a high intensity discharge lamp 4 includes a primary ballast for providing a primary current to the lamp 4, and a current injector which in the case shown comprises a control ballast 8 and a switch 9 (e.g. a triac) controlled by a control unit 12. The current injector injects a secondary current into the lamp 4 that is less than the primary current and can be varied by the control unit 12, e.g. by varying the amount of time within an a.c. cycle that the control ballast 8 is switched into the circuit. The controller 5 allows the lamp 4 to be controlled, for example, to operate at a constant power (variable light output) or at a constant light output (variable power).

Abstract: This invention presents a single-stage power converter for driving many number of Light-Emitting-Diode (LED). The power converter converts an AC input voltage into DC current source and regulates the current flowing into the LED. In addition, the AC input current is controlled to have a sinusoidal waveform synchronized with the AC input voltage so that AC input Power Factor is corrected. Hence, both of Power Factor Correction (PFC) and LED current regulation are obtained simultaneously by using a single power conversion stage. So higher efficiency with low cost can be obtained.

Abstract: A lower-cost ballast circuit for fluorescent lamps is provided. A resonant circuit is formed by a series connection of an inductor and a capacitor to operate the fluorescent lamp. A first circuit and a second circuit are coupled to switch the resonant circuit. Taking the first circuit for instance, a first resistor is connected in series with a first switch for generating a first control signal in response to a switching current of the first switch. The first switch is turned on once the first control signal is lower than a first zero-threshold. After a quarter resonant period of the resonant circuit, the first switch is turned off once the first control signal is lower than a first threshold. Therefore, a soft switching for the first switch is achieved.

Abstract: A display device in which a light shielding film is formed so as not to increase the number of steps and its cost, is provided. The display device of the present invention includes a monitor element for controlling influence on a light-emitting element due to temperature change and change with time and a TFT for driving the monitor element, and the TFT for driving the monitor element is provided so as not to be overlapped with the monitor element. The display device of the present invention includes a first light shielding film provided so as not to be overlapped with a first electrode of the monitor element, and a second light shielding film provided so as to be overlapped with an outer edge portion of the first electrode.

Abstract: The present invention discloses an organic light emitting diode capable of obtaining proper luminance and long life cycle by controlling an amount of current flowing through an organic electroluminescent device per unit pixel. The organic light emitting diode includes a luminescent device and first and second transistors for driving the luminescent device, wherein the first and second transistors have different resistance values. The first transistor is a driving transistor for driving the luminescent device. The second transistor is a switching transistor for switching on and off the driving transistor. The driving transistor may have a higher resistance value than the switching transistor.

Abstract: A dielectric waveguide integrated plasma lamp (DWIPL) with a body consisting essentially of at least one dielectric material having a dielectric constant greater than approximately 2, and having a shape and dimensions such that the body resonates in at least one resonant mode when microwave energy of an appropriate frequency is coupled into the body. A bulb positioned in at least one lamp chamber in the body contains a gas-fill which when receiving energy from the resonating body forms a light-emitting plasma.

Abstract: A dielectric waveguide integrated plasma lamp is disclosed for powering a small and bright bulb with a diameter of a few millimeters. The lamp is contained within a high dielectric constant material which guides the microwaves to the bulb, provides heat isolation to the drive circuit, contains the microwaves, provides structural stability and ease of manufacturing and allows efficient energy coupling to the bulb when used as a dielectric resonant oscillator.

Abstract: The light-emitting element has a problem that reliability, heat-resisting stability and durability are low because of the deterioration in an organic compound layer. The TFT for driving the light-emitting element has a problem that variation readily occurs in its electrical characteristic due to the defects existing in grain boundaries. The present invention provides a light-emitting device by using the fact that, by applying to the light-emitting element a drive voltage having a polarity reverse to that in light emission during each constant period, the light-emitting element is improved in current-voltage characteristic. Furthermore, the present invention provides a light-emitting device made not dependent upon transistor characteristic, by controlling the amount of a current flowing through the light-emitting element.

Abstract: A dielectric waveguide integrated plasma lamp is disclosed for powering a small and bright bulb with a diameter of a few millimeters. The lamp is contained within a high dielectric constant material which guides the microwaves to the bulb, provides heat isolation to the drive circuit, contains the microwaves, provides structural stability and ease of manufacturing and allows efficient energy coupling to the bulb when used as a dielectric resonant oscillator.

Abstract: A dielectric waveguide integrated plasma lamp is disclosed for powering a small and bright bulb with a diameter of a few millimeters. The lamp is contained within a high dielectric constant material which guides the microwaves to the bulb, provides heat isolation to the drive circuit, contains the microwaves, provides structural stability and ease of manufacturing and allows efficient energy coupling to the bulb when used as a dielectric resonant oscillator.

Abstract: The driving and control device according to the present invention provides a desired switched current to a load including a string of one or more electronic devices, and comprises one or more voltage conversion means, one or more dimming control means, one or more feedback element and one or more sensing means. The voltage conversion means may be a DC-to-DC converter for example and based on an input control signal converts the magnitude of the voltage from the power supply to another magnitude that is desired at the high side of the load. The dimming control element may comprise a switch such as a FET, BJT, relay, or any other type of switching device, for example, and provides control for activation and deactivation of the load.

Abstract: The present invention transforms existing electrical wall outlets into an emergency lighting system for homes, hospitals, hotels, nursing homes and businesses. The lighting device, designed as a replacement electrical wall outlet or receptacle, simply plugs into an existing dual outlet after removal of its faceplate. The lighting device continues to function as an electrical outlet, however, also comprises a local power source such as a constant charge lithium ion battery; a motion sensor for initiating a low level of lighting for darkened room or corridor transit; a power sensor for activating a high level of light when electrical service is disrupted, thereby broadcasting a wash of light over an otherwise darkened room or corridor; and a photoelectric cell which detects daylight or otherwise provided lighting of the room or corridor and thereby prevent unnecessary power usage.

Abstract: An object of the present invention is to provide a light emitting device that is able to suppress power consumption while a balance of white light is kept, without making a configuration of a power source circuit complicated. A power source potential corresponding to each color of a light emitting element is used as a higher electric potential of a video signal and an electric potential of a power source line in the case that a transistor for controlling a supply of electric current to the light emitting element is a p-channel TFT. Conversely, a power source potential corresponding to each color of a light emitting element is used as a lower electric potential of a video signal and an electric potential of a power source line in the case that a transistor for controlling a supply of electric current to the light emitting element is an n-channel TFT.

Abstract: In a lighting circuit for a discharge lamp, the discharge lamp is kept lit without fail when a DC input voltage becomes low, while avoiding a complicated circuit configuration and control method. A DC-AC converter circuit receives a DC input voltage and converts it to an AC voltage and boosts the AC voltage. The DC-AC converter circuit is controlled by a control means having a circuit for detecting the DC input voltage “+B” to perform a lighting control of the discharge lamp. The lighting circuit comprises a transformer for AC conversion, switching elements, and resonance capacitor. The switching elements are driven to cause a series resonance of the resonance capacitor and an inductance component of the transformer for AC conversion or an inductance element.

Abstract: A method and apparatus of driving a plasma display panel that is adaptive for making a stable operation at both a low temperature and a high temperature. In the apparatus, a scan driver applies a first sustaining pulse to a scan electrode during a sustain period. A sustain driver applies a second sustaining pulse alternating with the first sustaining pulse to a common sustain electrode during the sustain period. A sustain voltage source supplies a driving voltage to the scan driver and the sustain driver such that the first and second sustaining pulses can be applied. A controller controls a voltage value of the driving voltage in correspondence with a driving temperature at which the panel is driven.

Abstract: A dielectric waveguide integrated plasma lamp (DWIPL) with a body consisting essentially of at least one dielectric material having a dielectric constant greater than approximately 2, and having a shape and dimensions such that the body resonates in at least one resonant mode when microwave energy of an appropriate frequency is coupled into the body. A bulb positioned in at least one lamp chamber in the body contains a gas-fill which when receiving energy from the resonating body forms a light-emitting plasma.

Abstract: Methods and apparatus for generating strongly-ionized plasmas are disclosed. A strongly-ionized plasma generator according to one embodiment includes a chamber for confining a feed gas. An anode and a cathode assembly are positioned inside the chamber. A pulsed power supply is electrically connected between the anode and the cathode assembly. The pulsed power supply generates a multi-stage voltage pulse that includes a low-power stage with a first peak voltage having a magnitude and a rise time that is sufficient to generate a weakly-ionized plasma from the feed gas. The multi-stage voltage pulse also includes a transient stage with a second peak voltage having a magnitude and a rise time that is sufficient to shift an electron energy distribution in the weakly-ionized plasma to higher energies that increase an ionization rate which results in a rapid increase in electron density and a formation of a strongly-ionized plasma.

Abstract: A plasma source is described. The source includes a reactive impedance element formed from a plurality of electrodes. By providing such a plurality of electrodes and powering adjacent electrodes out of phase with one another, it is possible to improve the characteristics of the plasma generated.