Abstract: The invention provides a self-ballasted fluorescent lamp provided with a function for operating normally when the self-ballasted fluorescent lamp is inadvertently connected to a lighting fixture provided with a light bulb dimmer if the dimmer is at the maximum level, and with a function for reliably stopping operation of the ballast circuit if the dimmer is in a dimmed state and thereby latch the lamp in an unlit state and protect the ballast circuit. Even if the self-ballasted fluorescent lamp is connected to a power source via a light bulb dimmer, when a current detected by a current detection circuit exceeds a predetermined current value, a stop circuit stops operation of an inverter circuit and latches it in that stopped state in order to maintain the self-ballasted fluorescent lamp in an unlit state.

Abstract: An electrodeless discharge lamp includes: a bulb filled with discharge gas; an induction coil; a power supply circuit including a plurality of electric components; a case for accommodating the plurality of electric components; a stick-shaped heat conducting member; a first planar heat conducting member thermally connected to the stick-shaped heat conducting member; a second heat conducting member thermally connected to the first heat conducting member; and a third heat conducting member for thermally connecting at least two of the plurality of electric components, wherein the second heat conducting member is thermally connected to the case, and the thermal conductivity of the first heat conducting member is lower than the thermal conductivity of the stick-shaped heat conducting member and the thermal conductivity of the second heat conducting member.

Abstract: The present invention discloses an operating apparatus of discharge lamp comprising an AC/DC converter means for converting an ac voltage into a dc voltage, a DC/AC converter means for converting a dc output voltage of the AC/DC converter means into a high frequency ac voltage, a discharge lamp coupled to an output terminal of the DC/AC converter means, and a controller means by which the output of the DC/AC converter means is made variable according to an integrated value based on a half cycle of the ac voltage.

Abstract: A discharge lamp operating apparatus includes a discharge lamp and a driving circuit of the discharge lamp. The driving circuit can vary power to be supplied to the discharge lamp and has a function to turn off the discharge lamp at a supplied power value above a supplied power value at which unstable discharge occurs in the discharge lamp.

Abstract: A fluorescent lamp apparatus includes a fluorescent tube, a ballast circuit for lighting the fluorescent tube, a case for housing the ballast circuit and a holder provided at the end of the case for holding the fluorescent tube. The ballast circuit includes at least a first circuit board and a second circuit board, and the first and second circuit boards are arranged substantially perpendicular to each other in the case. This configuration can suppress an increase in the size of the apparatus and prevent thermal damage to the circuit elements during lamp operation.

Abstract: A dimmable self-ballasted fluorescent lamp includes a fluorescent lamp, a ballast and a lamp base that are formed as one unit. The ballast includes a preheating current supply circuit for supplying a preheating current to the fluorescent lamp; an inverter circuit portion for supplying a high frequency AC voltage to the fluorescent lamp; and a control circuit portion for controlling a driving frequency of the inverter circuit portion. The ballast is provided with an output current limiting element for limiting an output current from the preheating current supply circuit.

Abstract: Disclosed is a dimmable fluorescent lamp operating apparatus which comprises a fluorescent lamp, electrical characteristic detecting element for detecting an electrical characteristic of the fluorescent lamp, an inverter circuit for driving the fluorescent lamp, and a feedback controlling circuit for controlling the drive frequency of the inverter circuit such that the electrical characteristic of the fluorescent lamp becomes a predetermined value, wherein the feedback controlling circuit includes temperature detecting element for detecting the temperature of the fluorescent lamp and wherein the frequency characteristic bandwidth of the feedback controlling circuit is varied based on the detected fluorescent lamp temperature.

Abstract: A ballast for a discharge lamp includes a fluorescent lamp, an AC/DC conversion portion, a dimming control portion, and a DC/AC conversion portion. The AC/DC conversion portion converts a phase-controlled input AC voltage to a DC voltage. The dimming control portion calculates a dimming control signal from the input AC voltage. The DC/AC conversion portion converts the DC voltage from the AC/DC conversion portion to a high frequency AC voltage to be applied to the fluorescent lamp and lights and dims the lamp in response to the dimming control signal. The DC/AC conversion portion has a first operation mode for maintaining the lighting of the fluorescent lamp and for lighting and dimming the same and a second operation mode for supplying the fluorescent lamp with a voltage lower than the starting voltage of the lamp in its non-operating state. The conducting period of the phase-controlled AC voltage can be detected even in the non-operating state of the fluorescent lamp so as to restart the lamp.

Abstract: A discharge lamp operating apparatus includes a discharge lamp; a dimmer for performing phase-control with respect to an input power source; and a ballast circuit for dimming and operating the discharge lamp in accordance with an AC voltage that is phase-controlled by the dimmer. A relationship Z2≦(Vin/Vob−1)×Z1 is satisfied, where Z1 (&OHgr;) is an impedance between an input terminal and an output terminal of the dimmer, Vob (V) is a breakover voltage of a bidirectional trigger diode that applies a trigger signal and is connected to a gate terminal of a switching element included in the dimmer, vin (V) is an effective voltage of a commercial power source, and Z2 (&OHgr;) is an input impedance between the input terminals of the ballast circuit.

Abstract: A fluorescent lamp apparatus includes a fluorescent tube, a ballast circuit for lighting the fluorescent tube, a case for housing the ballast circuit and a holder provided at the end of the case for holding the fluorescent tube. The ballast circuit includes at least a first circuit board and a second circuit board, and the first and second circuit boards are arranged substantially perpendicular to each other in the case. This configuration can suppress an increase in the size of the apparatus and prevent thermal damage to the circuit elements during lamp operation.

Abstract: A discharge lamp operating apparatus includes a discharge lamp and a driving circuit of the discharge lamp. The driving circuit can vary power to be supplied to the discharge lamp and has a function to turn off the discharge lamp at a supplied power value above a supplied power value at which unstable discharge occurs in the discharge lamp.

Abstract: A metal halide lamp includes an arc tube containing at least mercury and metal halide. A pair of opposed main electrodes extend in the arc tube. A lamp voltage is applied between the main electrodes. The main electrodes have respective distal ends which are spaced from each other by a predetermined distance “d”.

Abstract: An operating apparatus of a discharge lamp for operating the discharge lamp having an arc tube defining a discharge space includes: generation means for generating a first waveform signal having a frequency component of an acoustic resonance frequency exciting a mode which straightens an arc discharge, a center line of a waveform of the first waveform signal being maintained at a fixed level; and modulation means for modulating the first waveform signal periodically so that a polarity of the center line of the first waveform signal changes alternately at a modulation frequency which is lower than the acoustic resonance frequency, and generating a modulated signal. A modulation depth .alpha./.beta., where .alpha. is a peak-to-peak amplitude of the first waveform signal and .beta. is an effective value of an amplitude of the modulated signal, is set at such a value that a sealed material in the arc tube is prevented from adhering to a center portion of the arc tube in substantially a strip shape.

Abstract: A discharge lamp operating apparatus has a glass envelope for defining a discharge space and a pair of electrodes which are hermetically sealed within the glass envelope and are opposed to each other. The apparatus includes (1) generation element for generating a waveform signal having an acoustic resonant frequency for exciting a mode, in which a discharge arc between the pair of electrodes is straightened and (2) modulation element for modulating the waveform signal so that a polarity of the center line of the waveform signal is alternately changed at a lower frequency than the acoustic resonant frequency. If the value of the amplitude of the waveform signal from peak to peak is .alpha., and the effective value of the modulated waveform signal is .beta., then the depth of modulation .alpha./.beta. at the beginning of operation is equal to or less than the depth of modulation .alpha./.beta. at an operation under rated condition.

Abstract: A fluorescent lamp operating apparatus is used for operating a fluorescent lamp, which includes a glass tube coated with a phosphor and has at least mercury sealed therein, by generating an electric field in a direction from an inner surface of the glass tube toward a center of the glass tube. The operating apparatus, for example, includes: a ballast circuit connected to the fluorescent lamp for starting the fluorescent lamp; a potential application member disposed so as to at least partially surround discharge plasma generated in the fluorescent lamp; and a potential application circuit for applying a potential to the potential application member. In such a case, the potential application circuit applies a potential to the potential application member which is higher than the potential of the discharge plasma.

Abstract: Upon generating arc discharge by inputting electric power which changes at a predetermined frequency to the discharge lamp horizontally disposed so as to operate the discharge lamp, the predetermined frequency is a frequency such that the arc discharge is excited substantially in a linear shape by acoustic resonance; and a value of the electric power to be input to the discharge lamp is set so that an input power value per unit inner volume of an arc tube of the discharge lamp falls within a predetermined range which is determined depending on a shape of the arc tube, thereby suppressing a strip-shaped adhesion of a sealed material of the arc tube to a tube wall in the vicinity of a center portion of the arc tube.

Abstract: A discharge lamp lighting device according to the present invention includes: a discharge lamp including an electrode; and a lighting circuit for lighting the discharge lamp, the lighting circuit being connected to the discharge lamp, wherein the discharge lamp includes a conductor at least partially surrounding the electrode, and the lighting circuit provides a potential for the conductor that is higher than an average potential of the electrode.

Abstract: An operating apparatus for a discharge lamp, which includes a pair of electrodes and an arc tube having a material enclosed therein, includes: a selective depositing device for selectively depositing the material on one electrode of the pair of electrodes when the discharge lamp is turned off; and a ballast circuit for starting operation of the discharge lamp and maintaining the operation under rated conditions. The ballast circuit includes a starting pulse generator for applying a starting pulse to the discharge lamp when the discharge lamp starts the operation. The starting pulse generates an electric field acting from the one electrode of the pair of electrodes having the material deposited thereon to the other electrode.

Abstract: An apparatus for operating a high intensity discharge lamp that minimizes discharge arc curvature to form a straight discharge arc and thereby eliminate variations in the discharge arc color caused by cataphoresis is disclosed. The apparatus outputs a synthesize wave having a waveform with a frequency component of the acoustic resonance frequency to excite a mode straightening the discharge arc, and a waveform of a frequency less than the acoustic resonance frequency whereby the polarity of the waveform having a frequency less than the acoustic resonance frequency changes. The acoustic resonance frequency is determined by the speed of sound in the discharge space, and the length of the discharge space intersecting the discharge arc.

Abstract: An apparatus that obtains a straight discharge arc during the whole lighting period, as well as provides a discharge lamp-lighting apparatus which can form a plurality of luminous intensity distribution patterns by changing the shape of the discharge arc. By supplying a lighting waveform equal to an acoustic resonance frequency which lighting waveform excites the mode to make the discharge arc straight. The acoustic resonance frequency is determined by the sound velocity in the discharge space medium and the height of a section orthogonal area to the electrode axis to the discharge lamp. The shape of the discharge arc at the time of rated lighting can be made substantially straight. By supplying the lighting waveform which amplifies the amplitude of the compressional wave emitted from the discharge arc during the period when the vapor pressure of the filler of the discharge lamp is low, the shape of the discharge arc can be made straight during the whole lighting period.