摘要:
An electrodeless inductively-coupled fluorescent lamp which operates at ro frequency comprising a bulbous envelope (1) filled with rare gas and metal vapor. A reentrant cavity (4) and an induction coil (6) are disposed in the cavity (4). The inner walls of the envelope (1) and the cavity (4) have a protective coating (3) and a phosphor coating (2). A metal Faraday cylinder (12) welded to the lamp base (13) is disposed between the cavity (4) and the coil (6) to reduce capacitive RF voltage between the coil and the plasma to improve lamp maintenance and remove heat. A tubulation (16) is disposed on the lamp axis to evacuate the envelope (1). The proximal end of the tubulation (16) has an expansion (20) with the volume (23) where the initial capacitive discharge is ignited. The RF coil voltage needed for the ignition of the capacitive discharge in the expansion area (23) is substantially lower than that needed for the ignition of the capacitive discharge in the area (14) along the inner cavity walls (4) to decrease the lamp starting voltage. In one of the embodiments of the present invention the expansion is conically shaped and in another it is cylindrically shaped and is used to generate the inductive plasma to increase the light generation in the top part of the bulb (28) and improve light output through the bulb top surface (27).
摘要:
An electrodeless lamp includes an envelope (1) containing a fill of discharge gas, a magnetic core t(7), an induction coil (6) wound around the magnetic core (7), a driver circuit for supplying an electric current to the induction coil (6) to operate the electrodeless lamp, a socket (10) for receiving electrical power supplied to the electrodeless lamp, and a heat conduction means (8,9) thermally coupled to the magnetic core (7) for conducting heat generated in the magnetic core (7) to the ambient atmosphere to dissipate heat therein, or coupled to the socket (10) for conducting heat generated in the magnetic core (7) to the socket to dissipate heat therethrough.
摘要:
An electrodeless compact fluorescent lamp operated at a frequency from 50 KHz to 1000 KHz and RF power from 10 W to 40 W is described. The lamp includes a bulbous glass envelope (1) filled with rare gas and metal vapor, reentrant glass cavity (2), an induction coil (6) made from Litz wire, a ferrite assembly comprising a ferrite core (7) and MnZn ferrite disk (11), a cooling structure comprising a metal (or ceramic) tube (8) positioned inside the ferrite core (7) and a metal (or ceramic) unit (9) that transmits the heat from the cavity and ferrite assembly to the Edison socket (10), a thermal shield (12), and a driver and matching network located inside the lamp base (13). A protective coating (15) and phosphor coating (16) are coated on the inner surface of the envelope (1) and reentrant cavity (2). The reflective coating (17) made from alumina is coated on the inner surface of the cavity (2) and on the outer surface of the envelope bottom (4). The mercury pressure is controlled in the envelope by the temperature of the amalgam (5) positioned in the tubulation (3) or by the temperature of pure mercury located in the cold spot.
摘要:
An electrodeless fluorescent lamp containing a fill of a rare gas and mercury and a flag (14) disposed therein at a predetermined location in the lamp for increasing the rate of luminous development in the lamp. The flag (14) includes a pair of spaced-apart metallic foil sections (31) and a metallic mesh substrate (30) disposed between the foil sections (31) whereby to be shielded from ion bombardment of the discharge. A coating (30a) of indium which is adapted to amalgamate with the mercury is disposed on the mesh (30). The sections are joined together by spot-welding (32) to enable migration of mercury into and out of the space between the sections thereby enable the atoms to form an amalgam with the indium and be rapidly released therefrom.
摘要:
An electrodeless fluorescent lamp and fixture is disclosed which operates radio frequencies and contains a metallic cylinder 9 to suppress capacitive coupling between an induction coil 7 and a plasma in the envelope 1 of the lamp and simultaneously substantially reduce heat in a reentrant cavity 5. The lamp includes a bulbous envelope 1 having a conventional phosphor layer 3 disposed therein. The bulbous envelope 1 contains a suitable ionizable gaseous fill. Upon ionization of the gaseous fill, the phosphor is stimulated to emit visible radiation upon absorption of ultraviolet radiation. The reentrant cavity 5 of the bulbous envelope 1 contains an inducation coil. The cylinder 9 transfers heat from the plasma to the fixture 11 through a base 13, 13a on the envelope 1.
摘要:
An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity and an envelope bottom, an electromagnetic coupler positioned within the reentrant cavity, and a thermal shield positioned in proximity to the envelope bottom and configured to increase the temperature of the envelope bottom. By increasing the temperature of the envelope bottom, a cold spot is prevented. As a result, light output at low temperatures is comparable to light output at room temperature.
摘要:
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.
摘要:
An electrodeless fluorescent lamp and fixture is disclosed which operates at radio frequencies and contains a bifilar coil to reduce RF voltage between the plasma and the coil and a metallic cylinder (10) to remove heat from a said bifilar coil. The bifilar coil consists of two windings. The primary (induction) winding (6) is used to generate RF electrical azimuthal field in the bulb volume needed to maintain the inductively-coupled RF plasma. The second (bifilar) winding (18) has essentially the same number of turns and is wound on the inductive winding (6), but in the direction opposite to that of the primary (inductive) winding. The RF current flowing in the inductive winding (6) induces an RF voltage of the opposite polarity in the bifilar winding (18), so two adjacent turns of both windings have equal (or nearly equal) but of opposite sign RF potentials with respect to the plasma. This results in the mutual "cancellation" of capacitive RF electric fields induced by both windings in the plasma and in a sheath formed between the plasma and the cavity walls. The reduction of the electric field in turn results in the lowering of a direct current voltage across the sheath thereby lowering the energy of ions which are accelerated in this sheath coating. The lowering of ion energy reduces the damage caused by ions and leads to improved maintenance and a longer life lamp.
摘要:
A compact fluorescent lamp is designed to imitate an incandescent lamp in size, shape and luminosity. The lamp includes a bulbous envelope (14) having an external shape of an incandescent lamp (10) on a standard Edison-type base (11) that enables it to be substituted for standard 60, 75 and 100 W incandescent lamps. A low-pressure fluorescent lamp (18) having a coiled tubular envelope with an outer diameter less than about 7 mm, an inner diameter between about 1 and 5 mm, and a length between about 50 and 100 cm is wound in a coil around the axis of the bulbous envelope (14) and is disposed within the bulbous envelope. The tubular envelope is formed of soft glass and has a fluorescent phosphor coating disposed on the inner surfaces. Electrodes (14) with external electrical contacts are disposed at each end of the envelope. A ballast (12) is disposed within the bulbous envelope. The ballast is electrically connected to the lamp (15), whereby to control current in the fluorescent lamp. A heat shield (17) is disposed between the lamp and the ballast to thermally isolate the lamp from the ballast, whereby heat from the lamp will not adversely affect the ballast.
摘要:
An electrodeless fluorescent lamp employs a glass envelope made from a single linear tube or bulb and a reentry cavity disposed on the envelope axis and sealed to the envelope. The envelope is filled with inert gas and mercury vapor. Phosphor and protective coatings are disposed on the inner surfaces of the envelope and the cavity. An induction coil of A few turns made from silver coated copper wire is wrapped around the envelope in its axial direction. The inductively-coupled axially uniform plasma is generated inside the envelope. The discharge electric field and current form a closed-loop path inside the envelope along its walls. The introduction of the reentry cavity decreases the lamp wall loading without loosing lamp power efficiency and efficacy. The lamp is operated at frequencies from 50 kHz to 200 MHz and RF power from 5 W to 2000 W without the use of ferrite inside of the reentry cavity.