Matsushita Electric Industrial Co., Ltd.

Shigeru Horii

Satoshi Kominami

Kouji Miyazaki

Koji Miyazaki

Kazuhiko Ito

Masataka Ozawa

Nobuhisa Yoshikawa

Kazutaka Koyama

Takayuki Kamitani

Atsuo Waki

Mamoru Takeda

Takeshi Saito

Tomizo Matsuoka

Masayoshi Gyoten

Masakatsu Kichibayashi

Shozo Oshio

Makoto Horiuchi

Teruaki Shigeta

Akira Hochi

Koji Kitamura

Takeshi Nishiura

Tatsushi Higuchi

Masakatsu Ozawa

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.

Method and apparatus for operating a discharge lamp to reduce the

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.

Fluorescent lamp operating apparatus

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.

Method and apparatus for operating discharge lamp

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.

Discharge lamp lighting device and a method for lighting a discharge lamp

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.

Operating apparatus for discharge lamp

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.

Discharge lamp operating apparatus and method for reducing discharge arc

An alkaline earth metal compound containing no fluorine atoms in its molecules, a rare earth compound containing no fluorine atoms in its molecules, and an aluminum compound containing no fluorine atoms in its molecules are fired in a high-temperature reducing atmosphere ranging from 1600.degree. to 2000.degree. C., so that an aluminate phosphor, the particle diameter and shape thereof are controlled, is provided. A mixture of 22 wt % of barium carbonate, 11 wt % of basic magnesium carbonate, 65 wt % of spherical alpha-alumina of 10 .mu.m diameter and 2 wt % of europium oxide is fired in a mixed gas atmosphere consisting of gaseous hydrogen of 5 volume % and gaseous nitrogen. The temperature is raised at 400.degree. C./hr, and lowered at 400.degree. C./hr after firing for two hours at 1700.degree. C. As a result, a spherical aluminate phosphor of 10 .mu.m diameter, which is expressed by formula (Ba.sub.0.9,Euo.sub.0.1)MgAl.sub.10 O.sub.17 is obtained.

Method for producing aluminate phosphor

The apparatus has a light transmitting bulb for confining a discharge therein, a fill sealed within the light transmitting bulb and including a rare gas and a metal halide emitting a continuous spectrum by molecular radiation, and a discharge excitation source for applying electrical energy to the fill and for starting and sustaining an arc discharge, and the metal halide includes one kind of halide selected from the group consisting of an indium halide, a gallium halide, and a thallium halide, or a mixture thereof, and in that the light transmitting bulb has no electrodes exposed in discharge space and further this construction utilizes the continuous spectrum of molecular radiation of the metal halide and thereby achieves high color rendering properties and high luminous efficacy simultaneously without using mercury as the fill.

Electrodeless hid lamp and electrodeless hid lamp system using the same

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. By changing the ratio of the acoustic resonance frequency component, the shape of the discharge arc can be changed.

Discharge lamp-lighting apparatus for straightening arc discharge

The present invention relates to an inverter driven lamp arrangement. The arrangement provides for the sensing of both lamp voltage and current. The arrangement also provides for a large current during times of low voltage and a small current during times of high voltage. The sensing of lamp current is done by a current detector that is connected to a resonance circuit whose output is applied in signal form to a lamp start control circuit. The resonant circuit is a series connected resonant circuit composed of a choke coil and a first capacitor. This series connected arrangement is further connected in series with a second non-resonant capacitor. Also the arrangement includes circuitry to gradually reduce the frequency of the inverter just after the lamp starts.

An inverter driven lamp arrangement having a current detection circuitry

In a discharge-lamp lighting apparatus for lighting a discharge lamp such as a metal halide lamp, there is provided a lighting control circuit which controls its output in a starting time of the discharge lamp in response to at least a length of the last off-time and an on-time after the start of discharging; and a power supplied to the discharge lamp is controlled in accordance with this output of the lighting control circuit.

Apparatus for controlling the power to a discharge-lamp

When a discharge lamp is started, high voltage pulses which superpose the voltage due to LC resonance of a resonance circuit are supplied to the discharge lamp, and breakdown occurs in the discharge lamp. The pulse energy needed for the high voltage pulses is small and the output power of the resonance circuit can be decreased. After the breakdown, the energy needed for the transfer from glow discharge to arc discharge is supplied by the resonance, and the high voltage pulses used to supply the starting energy are allowed to be stopped. Thus, the starting and restriking of a discharge lamp is sure, and the starting circuit for a discharge lamp can be made more compact.

Discharge lamp starting circuit

A discharge lamp apparatus is capable of securely detecting the decrease of emission in the terminal stage of the life of a discharge lamp by connecting a voltage detecting circuit to the discharge lamp, and a discharge lamp apparatus for securely starting, operating and dimming the discharge lamp, and is also capable of protecting the lamp in the event of abnormality; the apparatus includes two timer circuits, a reset circuit, a dimmer circuit, an abnormality detecting circuit, and a stopping circuit.

Discharge lamp operation apparatus

An apparatus is provided for driving a discharge lamp, the discharge lamp having first and second electrodes, each of the first and second electrodes having first and second terminals. The apparatus includes a switching circuit coupled to the first terminals of the first and second electrodes of the discharge lamp for supplying a high frequency signal to the discharge lamp for igniting the discharge lamp. A starting circuit is provided connected to the second terminals of the first and second electrodes of the discharge lamp and including an inductor and capacitor connected in parallel across the discharge lamp. Alternately, a thermister is provided between parallel connected conductor and capacitor and one of the second terminals of the first electrode of the discharge lamp. Furthermore, circuitry is provided which is connected between the switching circuit and the thermister for deactivating the switching circuit when the thermister is heated to a specified temperature.

Apparatus for igniting a discharge lamp including circuitry for

A high pressure discharge lamp apparatus comprises:

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Takatsuki, Japan

Shigeru Horii