Technical Field
[0001] The present invention relates to an electrodeless fluorescent lamp and a lighting
apparatus thereof.
Background Art
[0002] In an electrodeless fluorescent lamp, no electrode is provided in a bulb which is
made of a glass, so that non-lighting due to blowout of electrode or erosion of emitter
(thermo-electronic emission material) may not occur, and thereby, it has a characteristic
of longer operating life in comparison with a general fluorescent lamp in which a
pair of electrodes is arranged in a glass tube.
[0003] A constitution of a conventional electrodeless fluorescent lamp which is, for example,
shown in Japanese Laid-Open Patent Publication No.
7-272688 is shown in FIG. 3. This electrodeless fluorescent lamp has a bulb 20 formed of a
transparent material such as a glass, and into which a rare gas and a metal (for example,
mercury) that can be vaporized are filled. An outer shape of the bulb 20 is a rotation
symmetric body of substantially spherical, and a cavity 21 of substantially cylindrical
shape is formed around an axis of the rotation symmetry. A power coupler unit 27,
in which an induction coil 24 is wound around an outer periphery of a rod shaped core
23, is fitted to the cavity 21. Furthermore, a fluorescent material film 22 is formed
on an inner wall of the bulb 20.
[0004] A high frequency electromagnetic field occurs in the bulb 20 by applying a high frequency
current to the induction coil 24 from a high frequency power source 25 through cables
26, so that rare gas filled in the bulb 20 discharges electricity due to the high
frequency electromagnetic field. The bulb 20 is heated by the electric discharge,
and thereby mercury is evaporated (vaporized), and mercury vapor is further excited
in a discharge space of the bulb 20, so that ultra-violet rays are emitted. Ultra-violet
rays are further converted to visible lights with the fluorescent material film 22
formed on the inner wall of the bulb 20.
[0005] By the way, in the above mentioned electrodeless fluorescent lamp, an amalgam comprised
of an alloy of a base substance metal and mercury is enclosed in the bulb for a purpose
of getting stable quantity of light in a broad temperature environment. Mercury vapor
pressure in the discharge space is controlled with saturated vapor pressure at a temperature
of a point where the amalgam is disposed. If the temperature of the base substance
metal is constant, mercury vapor pressure in the discharge space does not vary. However,
there are going out and coming in of mercury on a surface of the amalgam even in the
saturated state, so that evaporation and liquefaction of mercury are repeated. Thus,
when the electrodeless fluorescent lamp has been lighted for a long time, mercury
included in the amalgam is consumed, and an amount of mercury corresponding to the
consumption is evaporated from the surface of the amalgam and supplied to the discharge
space. Hereupon, a quantity of the amalgam enclosed in the bulb is generally several
tens to several hundreds mg, and a rate of content of mercury is several %. In contrast,
since an amount of mercury necessary for maintaining the mercury vapor pressure in
the discharge space is several _g, there is enough amount of mercury for consumption.
[0006] However, when the electrodeless fluorescent lamp is lighted under a state where the
temperature in the bulb is not sufficiently increased such as for use in cool-temperature
environment or in dimming lighting, or when the amalgam is enclosed at a position
where the temperature is lower in the bulb, the temperature of the amalgam may be
lower and the amalgam may be in solid-phase even though the electrodeless fluorescent
lamp is lighted. When the electrodeless fluorescent lamp has been lighted continuously
under such condition for a long time, mercury may evaporate from the surface of the
amalgam to be supplied as mercury consumed in the discharge space. However, since
the amalgam is in solid-phase, diffusion of mercury is slower, and suppliance of mercury
from inside to surface of the amalgam needs long time. Thus, mercury on the surface
of the amalgam which is to be supplied to the discharge space becomes insufficient,
and output of light of the electrodeless fluorescent lamp may be deteriorated.
[0007] US 5 773 926 A discloses an electrodeless fluorescent RF lamp which includes a bulbous lamp envelope
with a top, a bottom and a fil of rare gas and vaporizable amalgam therein. A reentrant
cavity is disposed adjacent the bottom of the envelope and at least one tubulation
extends from the envelope to hold at least a portion of the vaporizable amalgam. An
induction coil is disposed on lead wires and coupled with a radio frequency exitation
generator for generation of a plasma to produce radiation.
[0008] EP 1 050 897 A discloses an electrodeless fluorescent lamp whereby a ferrite core is utilized to
generate magnetic and electric fields to maintain the discharge, and wherein a specific
core material of Mn-Zn combination is used which is added to Fe203 base to obtain
favorable grain boundary and crystalline structure.
[0009] US 2001/000941 A1 discloses an electrodeless lamp including an envelope containing a fill of discharge
gas, a magnetic core, an induction coil wound around the magnetic core, a driver circuit
for supplying an electric current to the induction coil, a socket for receiving electrical
power, and heat conduction means for conducting heat gnerated in the magnetic core.
Disclosure of Invention
[0010] A purpose of the present invention is to solve the above-mentioned problem and to
provide an electrodeless fluorescent lamp and a lighting apparatus thereof with which
enough quantity of metal vapor can be supplied to a discharge space in a bulb from
an amalgam, even when the electrodeless fluorescent lamp is lighted in a state where
the temperature in the bulb is not increased sufficiently such as for use in cool-temperature
environment or in dimming lighting.
[0011] An electrodeless fluorescent lamp in accordance with an aspect of the present invention
is characterized by comprising:
a bulb formed of a transparent material, into which a rare gas and a metal which can
be vaporized are filled, and having a cavity protruding inward;
a tubular shaped portion formed in the cavity that an inside thereof is communicated
to an inside of the bulb;
a fluorescent material film formed on an inner wall of the bulb;
an induction coil wound around a periphery of the tubular shaped portion along an
axial direction and contained in the cavity;
an amalgam containing the metal and disposed in the tubular portion; wherein
the amalgam is contained in a metal container, and the metal container is located
between an upper end and a bottom end of the induction coil inside the induction coil;
the amalgam contained in the metal container is heated by heat generation of the induction
coil or heat generation due to electric discharge under a state that the induction
coil is energized, so that the amalgam becomes a mixture of liquid-phase and solid-phase.
[0012] According to such a constitution, even when the electrodeless fluorescent lamp is
lighted under the state where the temperature in the bulb is not increased sufficiently
such as for use in cool-temperature environment or in dimming lighting, the amalgam
becomes the mixture of liquid-phase and solid-phase because the amalgam is heated,
so that mercury can be evaporated from a surface of the amalgam and enough amount
of mercury can be supplied to the discharge space in the bulb. Consequently, deterioration
of light output of the electrodeless fluorescent lamp due to insufficiency of mercury
on the surface of the amalgam which is to be supplied to the discharge space can be
prevented.
Brief Description of Drawings
[0013]
- FIG. 1A
- is a sectional view showing a constitution of an electrodeless fluorescent lamp in
accordance with an embodiment of the present invention, and FIG. 1B is a sectional
view showing a state where a lamp unit and a power coupler unit of it are departed.
- FIG. 2
- is a sectional view showing a constitution of a main portion of the electrodeless
fluorescent lamp in accordance with the above embodiment.
- FIG. 3
- is a sectional view showing a constitution of a conventional electrodeless fluorescent
lamp.
Best Mode for Carrying Out the Invention
[0014] An electrodeless fluorescent lamp and a lighting apparatus thereof in accordance
with an embodiment of the present invention are described with reference to drawing.
In the electrodeless fluorescent lamp and the lighting apparatus thereof, an amalgam
is heated to be mixture of liquid-phase and solid-phase even when the electrodeless
fluorescent lamp is lighted under a state where a temperature in a bulb is not increased
sufficiently such as for use in cool-temperature environment or in dimming lighting,
so that deterioration of light output of the electrodeless fluorescent lamp is prevented
with evaporation of mercury from a surface of the amalgam and suppliance of enough
amount of mercury to a discharge space in the bulb, as mentioned above.
[0015] As shown in FIG. 1A and FIG. 1B, the electrodeless fluorescent lamp in accordance
with this embodiment is constituted by a lamp unit 1 and a power coupler unit 10,
and the lamp unit 1 is detachably attached to the power coupler unit 10. The lamp
unit 1 has a bulb 2 formed of a transparent material such as a glass, and a ferule
3 of a substantially tubular shape fixed on a neck portion of the bulb 2.
[0016] An outer shape of the bulb 2 is rotation symmetry of a substantially spherical shape,
and a cavity 4 of a tubular shape having a bottom is formed around an axis of the
rotation symmetry. Specifically, a tubular shaped body serving as the cavity 4 is
adhered to a substantially spherical shaped body which is formed to be opened at a
bottom of a neck portion, so as to close the bottom of the neck portion and to protrude
inwardly toward the inside of the bulb 2. A ventilation pipe 5 is further adhered
on the bottom of the tubular shaped body so as to be coaxial with the center axis
of the tubular shaped body. The inside of the bulb 2 is communicated with an exterior
through the ventilation pipe 5, so that air in the inside of the bulb 2 is exhausted
and a rare gas (for example, argon gas) is filled into the inside of the bulb 2 through
the ventilation pipe 5. A fluorescent material film 6 is formed on inner peripheral
faces of the bulb 2 (an inner peripheral surface of the substantially spherical shaped
body and an outer peripheral surface of the substantially cylindrical shaped body
(SIC)) with spreading a fluorescent material. Then, the inside of the bulb 2 serves
as a discharge space.
[0017] Lower end portion of the ventilation pipe 5 is drawn outward from the bottom of the
neck portion of the bulb 2. After exhausting air from and filling the rare gas into
the bulb 2 as mentioned above, a metal container 7 containing the amalgam and a glass
rod 8 are put into the inside of the ventilation pipe 5, and the lower end thereof
is sealed under such state. Thereby, the bulb 2 is air-tightly sealed. Furthermore,
protrusions 5a and 5b respectively protruding inward are formed at upper and middle
portions of the exhausting pipe 5, and the metal container 7 is held between the protrusion
5b at the middle portion and the rod 8.
[0018] Material of the ventilation pipe 5 is not limited in particular, it, however, is
preferable to be formed of a material, which has a higher thermal conductivity than
that of a glass, such as a metal or a ceramic (for example, aluminum oxide, aluminum
nitride, boron nitride, silicon carbide, silicon nitride, beryllium oxide). Thereby,
heat generation of an induction coil 13 or heat generation due to electric discharge
can be conducted to the metal container 7 effectively, and thus, the amalgam in the
metal container 7 can be heated. In case of metal ventilation pipe 5, the coefficient
of thermal expansion of the metal should be coincided with that of a glass of the
tubular shaped body forming the cavity 4, and the pipe should be adhered on the bottom
face of the tubular shaped body with heat welding. Alternatively, in case of ceramic
ventilation pipe 5, it should be joined on the bottom face of the tubular shaped body
with frit of low-melting glass.
[0019] The metal container 7 is formed in a shape of capsule inside of which is hollowed,
and through-holes (not illustrated) are formed on a side face thereof. The amalgam
is contained in the inside of the metal container 7, and mercury goes out from and
comes into a surface of the amalgam through the through-holes. The amalgam contains
mercury at component proportion of 3.5% to base substance metal consisting of an alloying
with, for example, bismuth and indium.
[0020] An end portion of a supporting member 9, which is formed in a shape of substantially
horse shoe shape with square corners, is engaged with the protrusion 5a formed at
the upper portion of the ventilation pipe 5. A flag 9a, to which a metallic compound
(for example, hydration cesium) having a small work function is applied, is fixed
at another end portion of the supporting member 9 drawn from the ventilation pipe
5 toward the inside space of the bulb 2. The metallic compound applied to the flag
9a bears a function for increasing a number of electrons at starting up of the electrodeless
fluorescent lamp.
[0021] The power coupler unit 10 comprises a heat radiation cylinder 11 of substantially
cylindrical shape and having an outward flange portion 11a formed at a lower end thereof,
a cylindrical ferrite core 12 fixed on an upper end face of the heat radiation cylinder
11, and the induction coil 13 wound around an outer periphery of the ferrite core
12. Then, as shown in FIG. 1A, the power coupler unit 10 is attached to the lamp unit
1 in a manner so that the ventilation pipe 5 is inserted into an inside of the ferrite
core 12, the heat radiation cylinder 11, the ferrite core 12 and the induction coil
13 of the power coupler unit 10 are fit into the cavity 4 of the lamp unit 1. In a
state that the power coupler unit 10 is attached to the lamp unit 1, as shown in FIG.
2, the metal container 7 containing the amalgam is located between an upper end A
and a bottom end B of the induction coil 13 inside the induction coil 13.
[0022] Since the metal container 7 containing the amalgam is located inside the induction
coil 13 in the ventilation pipe 5, that is, in the vicinity of a position where electric
discharge occurs in the inside space of the bulb 2, the amalgam contained in the metal
container 7 is heated by heat generation of the induction coil 13 or heat generation
due to electric discharge under a state that the induction coil 13 is energized, that
is, in a state that the electrodeless fluorescent lamp is lighted. Therefore, the
amalgam can easily become a mixture of liquid-phase and solid-phase. Thus, even when
the electrodeless fluorescent lamp is lighted in a state that the temperature in the
bulb is not increased sufficiently such as for use in cool-temperature environment
or in dimming lighting, the temperature of the amalgam in the metal container 7 is
increased during a relatively short time, and the amalgam becomes the mixture of liquid-phase
and solid-phase, so that mercury can be evaporated from a surface of the amalgam for
supplying mercury consumed in the discharge space.
[0023] The induction coil 13 of the power coupler unit 10 is connected to a lighting apparatus
15 which comprises a high frequency power source, and a high-frequency current (for
example, a sinusoidal current of frequency 130 kHz) is applied to the induction coil
13 from the high frequency power source. Thereby, electric discharge occurs in the
discharge space inside the bulb 2, and the electrodeless fluorescent lamp is lighted.
In this embodiment, a high-frequency current for induction heating is superimposed
on an output current of the high frequency power source with applying amplitude modulation
of high frequency (for example, 500 kHz), according to need. According to the superimposed
high frequency current, it is possible to heat the metal container 7 directly by induction
heating with high frequency magnetic field generated in the induction coil 13. Therefore,
even in the cool-temperature environment, the amalgam contained in the metal container
7 can be heated with induction heating of the metal container, so that the amalgam
can become the mixture of liquid-phase and solid-phase, and can easily be maintained
in such state. In particular, since the metal container 7 is located inside the induction
coil 13, the induction heating can be performed effectively. Since mercury is easily
diffused in liquid-phase, it is possible to maintain enough amount of mercury on the
surface of the amalgam for supplying mercury vapor to the discharge space. Consequently,
even when the electrodeless fluorescent lamp is lighted under the state that the temperature
in the bulb is not increased sufficiently such as for use in cool-temperature environment
or in dimming lighting, mercury is evaporated from the surface of the amalgam for
supplying consumed mercury in the discharge space, so that enough quantity of mercury
is supplied to the discharge space. As a result, the light output of the electrodeless
fluorescent lamp is not deteriorated.
[0024] Besides, with respect to the superposition of current for superimposing the high
frequency current for induction heating on the output current of the high frequency
power source with amplitude modulation, it can be realized with using a known modulation
circuit, so that illustration and description of detailed constitution are omitted.
Furthermore, although timing and term for superimposing the high frequency current
for induction heating on the output current of the high frequency power source is
mot limited in particular, it may be performed in, for example, a constant term from
starting up of lighting of the electrodeless fluorescent lamp, or it may be performed
when a detected temperature of a sensor is equal to or lower than a predetermined
threshold with using the sensor such as a thermistor.
[0025] Still furthermore, the electrodeless fluorescent lamp in accordance with the present
invention is not limited to the above mentioned embodiment. It is sufficient to comprise:
a bulb formed of a transparent material, into which a rare gas and a metal which can
be vaporized are filled, and having a cavity protruding inward; a tubular shaped portion
formed in the cavity that an inside thereof is communicated to an inside of the bulb;
a fluorescent material film formed on an inner wall of the bulb; an induction coil
wound around a periphery of the tubular portion along an axial direction and contained
in the cavity; an amalgam containing the metal and disposed in the tubular portion;
and a heating means for heating the amalgam so that the amalgam becomes a mixture
of liquid-phase and solid-phase in a state where electric discharge occurs in a discharge
space inside the bulb. Other shapes and constitutions are not limited in particular.
Thereby, even when the electrodeless fluorescent lamp is lighted in a state that temperature
in the bulb is not increased sufficiently such as for use in cool- temperature environment
or in dimming lighting, the amalgam becomes a state of mixture of liquid-phase and
solid-phase due to the amalgam is heated, so that mercury is evaporated from a surface
of the amalgam and enough quantity of mercury is supplied to a discharge space inside
the bulb. As a result, deterioration of light output of the electrodeless fluorescent
lamp caused by insufficiency of mercury on the surface of the amalgam which is to
be supplied to the discharge space can be prevented.
[0026] This application is based on Japan Patent Application No.
2004-000557, and contents of which should be consequently incorporated with the present invention
with reference to the description and drawings of the above Patent Application.
[0027] Although the present invention has been fully described by way of example with reference
to the accompanying drawings, it is to be understood that various changes and modifications
will be apparent to those skilled in the art. Therefore, unless otherwise such changes
and modifications depart from the scope of the present invention, they should be construed
as being included therein.
1. An electrodeless fluorescent lamp comprising:
a bulb (2) formed of a transparent material, into which a rare gas and a metal which
can be vaporised are filled, and having a cavity (4) protruding inward,
a tubular shape portion (5) formed in the cavity (4) that an inside thereof is communicated
to an inside of the bulb,
a fluorescent material film (6) formed on an inner wall of the bulb (2), and
an induction coil (13) wound around a periphery of the tubular shaped portion (5)
along an axial direction and contained in the cavity,
an amalgam containing the metal and disposed in the tubular shaped portion (5)
characterized in that
the amalgam is contained in a metal container (7), and the metal container (7) is
located between an upper end and a bottom end of the induction coil (13) inside the
induction coil (13);
the amalgam contained in the metal container (7) is heated by heat generation of the
induction coil (13) or heat generation due to electric discharge under a state that
the induction coil (13) is energized, so that the amalgam becomes a mixture of liquid-phase
and solid-phase.
2. The electrodeless fluorescent lamp in accordance with claim 1, wherein the tubular
shaped portion (5) is formed of a material having higher heat-conductivity in comparison
with that of a transparent material used for forming the bulb (2), serves as a part
of the heating means so as to conduct heat generation of the induction coil (13) or
heat generation due to electric discharge to the amalgam effectively, and thereby
to heat the amalgam.
3. The electrode less fluorescent lamp in accordance with claim 2, wherein metal or ceramic
is used as the material having higher heat-conductivity of the tubular shaped portion
(5).
4. The electrodeless fluorescent lamp in accordance with claim 1, wherein the metal container
(7) and the induction coil (13) serve as a part of the heating means so as to heat
the metal container (7) with induction heating by applying high frequency current
for induction heating to the induction coil with superimposing on high frequency current
for discharging the rare gas in the inside of the bulb.
5. A lighting apparatus (15) arranged for lighting an electrodeless fluorescent lamp
according to one of the claims 1 to 4, comprising a high frequency power source (25)
for generating a high frequency current and a current superimposing means for superimposing
a current for induction heating on the high frequency current outputted from the high
frequency power source, and thereby, said metal container (7) provided inside said
bulb (2) of the electrodeless fluorescent lamp is heated with induction heating by
applying the current for induction heating to the induction coil (13) of the electrodeless
fluorescent lamp.
1. Elektrodenlose Fluoreszenzlampe, umfassend:
einen aus einem transparenten Material gebildeten Lampenkörper (2), in den ein Edelgas
und ein verdampfbares Metall eingefüllt sind und der einen nach innen ragenden Hohlraum
(4) hat,
einen im Hohlraum (4) gebildeten röhrenförmigen Abschnitt (5), dessen Innenraum mit
einem Innenraum des Lampenkörpers in Verbindung gesetzt ist,
eine Dünnschicht (6) aus fluoreszierendem Material, die an einer Innenwand des Lampenkörpers
(2) gebildet ist, und
eine Induktionsspule (13), die entlang einer Axialrichtung um einen Umfang des röhrenförmigen
Abschnitts (5) gelegt und in dem Hohlraum enthalten ist,
ein Amalgam, welches das Metall enthält und das im röhrenförmigen Abschnitt (5) angeordnet
ist,
dadurch gekennzeichnet, dass
das Amalgam in einem Metallbehälter (7) enthalten ist, und der Metallbehälter (7)
zwischen einem oberen Ende und einem unteren Ende der Induktionsspule (13) innerhalb
der Induktionsspule (13) sitzt;
das im Metallbehälter (7) enthaltene Amalgam durch Wärmeerzeugung der Induktionsspule
(13) oder Wärmeerzeugung aufgrund einer elektrischen Entladung in einem Zustand, in
welchem die Induktionsspule (13) mit Strom versorgt ist, erwärmt wird, so dass das
Amalgam zu einem Gemisch aus einer Flüssigphase und einer Feststoffphase wird.
2. Elektrodenlose Fluoreszenzlampe nach Anspruch 1, wobei der röhrenförmige Abschnitt
(5) aus einem Material mit einer höheren Wärmeleitfähigkeit verglichen mit derjenigen
eines zur Bildung des Lampenkörpers (2) verwendeten Materials gebildet ist und als
Teil der Erwärmungseinrichtung dient, um eine Wärmeerzeugung der Induktionsspule (13)
oder Wärmeerzeugung aufgrund einer elektrischen Entladung wirksam zum Amalgam zu leiten
und dadurch das Amalgam zu erwärmen.
3. Elektrodenlose Fluoreszenzlampe nach Anspruch 2, wobei Metall oder Keramik als das
über eine höhere Wärmeleitfähigkeit verfügende Material des röhrenförmigen Abschnitts
(5) verwendet wird.
4. Elektrodenlose Fluoreszenzlampe nach Anspruch 1, wobei der Metallbehälter (7) und
die Induktionsspule (13) als Teil der Erwärmungseinrichtung dienen, um den Metallbehälter
(7) mittels Induktionserwärmung zu erwärmen, indem ein Hochfrequenzstrom zur Induktionserwärmung
an die Induktionsspule angelegt wird, der dem Hochfrequenzstrom zur Entladung des
Edelgases im Innenraum des Lampenkörpers überlagert ist.
5. Leuchtsteuerungsgerät (15), das dazu eingerichtet ist, eine elektrodenlose Fluoreszenzlampe
nach einem der Ansprüche 1 bis 4 leuchten zu lassen, mit einer Hochfrequenzstromquelle
(25) zum Erzeugen eines Hochfrequenzstroms und einer Stromüberlagerungseinrichtung,
um dem von der Hochfrequenzstromquelle abgegebenen Hochfrequenzstrom einen Strom zur
Induktionserwärmung zu überlagern, wodurch der innerhalb des Lampenkörpers (2) der
elektrodenlosen Fluoreszenzlampe vorgesehene Metallbehälter (7) mittels Induktionserwärmung
durch Anlegen des Stroms zur Induktionserwärmung an die Induktionsspule (13) der elektrodenlosen
Fluoreszenzlampe erwärmt wird.
1. Lampe fluorescente sans électrode comprenant :
une ampoule (2) formée en un matériau transparent, à l'intérieur de laquelle un gaz
rare et un métal qui peut être vaporisé sont remplis, et comportant une cavité (4)
faisant saillie vers l'intérieur,
une partie de forme tubulaire (5) formée dans la cavité (4) de telle sorte que son
intérieur soit en communication avec un intérieur de l'ampoule,
un film en matériau fluorescent (6) formé sur une paroi interne de l'ampoule (2),
et
une bobine d'induction (13) enroulée autour d'une périphérie de la partie de forme
tubulaire (5) suivant une direction axiale et contenue dans la cavité,
un amalgame contenant le métal et disposé dans la partie de forme tubulaire (5),
caractérisée en ce que :
l'amalgame est contenu dans un conteneur en métal (7), et le conteneur en métal (7)
est localisé entre une extrémité supérieure et une extrémité de fond de la bobine
d'induction (13) à l'intérieur de la bobine d'induction (13) ;
l'amalgame contenu dans le conteneur en métal (7) est chauffé par génération de chaleur
de la bobine d'induction (13) ou par génération de chaleur due à une décharge électrique
sous un état dans lequel la bobine d'induction (13) est alimentée de telle sorte que
l'amalgame devienne un mélange de phase liquide et phase solide.
2. Lampe fluorescente sans électrode selon la revendication 1, dans laquelle la partie
de forme tubulaire (5) est formée en un matériau présentant une conductivité thermique
plus élevée que celle d'un matériau transparent utilisé pour former l'ampoule (2),
elle joue le rôle de partie du moyen de chauffage de manière à réaliser la génération
de chaleur de la bobine d'induction (13) ou la génération de chaleur due à une décharge
électrique sur l'amalgame de manière efficace et afin d'ainsi chauffer l'amalgame.
3. Lampe fluorescente sans électrode selon la revendication 2, dans laquelle un métal
ou une céramique est utilisé(e) en tant que matériau présentant une conductivité thermique
plus élevée de la partie de forme tubulaire (5).
4. Lampe fluorescente sans électrode selon la revendication 1, dans laquelle le conteneur
en métal (7) et la bobine d'induction (13) jouent le rôle d'une partie du moyen de
chauffage de manière à chauffer le conteneur en métal (7) par chauffage par induction
en appliquant un courant haute fréquence pour chauffer par induction sur la bobine
d'induction en superposant dessus le courant haute fréquence pour décharger le gaz
rare dans l'intérieur de l'ampoule.
5. Appareil d'éclairage (15) agencé pour éclairer une lampe fluorescente sans électrode
selon l'une des revendications 1 à 4, comprenant une source de puissance haute fréquence
(25) pour générer un courant haute fréquence et un moyen de superposition de courant
pour superposer un courant pour le chauffage par induction sur le courant haute fréquence
émis en sortie depuis la source de puissance haute fréquence et ainsi, ledit conteneur
en métal (7) prévu à l'intérieur de ladite ampoule (2) de la lampe fluorescente sans
électrode est chauffé par chauffage par induction en appliquant le courant pour le
chauffage par induction sur la bobine d'induction (13) de la lampe fluorescente sans
électrode.