RO119397B1 - Fluorescent tube - Google Patents

Abstract

The invention relates to a low-pressure mercury vapour fluorescent tube, with reduced switching on and electric power functioning, generally provided with hot cathode (filaments) or with electrodes. According to the invention, the fluorescent tube uses a volume of a gasodynamic medium between an outer classical pipe with luminophore on the intrados and filaments at its closed ends, and a dielectric inner pipe (2), closed at its ends, and concentrically suspended with the pipe (1), the entire volume of the pipe, which is vacuumed or filled, does not take part in the electric discharge. The electric power for functioning is reduced proportional with the reduction of the gasodynamic volume.

Description

The invention relates to a fluorescent tube, for electric lighting, with mercury vapor, low pressure, with significantly reduced electrical power compared to the classic fluorescent tube, equivalent in geometric dimensions and lighting performance.

Fluorescent tubes, also known as tabular fluorescent lamps or fluorescent lamps, are, in fact, fluorescent tubes with low pressure mercury (Hg) vapor discharges and hot cathode (filaments) in general.

Fluorescent tubes are made in the form of a straight cylinder with different lengths and diameters, but also in the form of a circle, circle arc, or U-shaped tube.

In the following, we will specify that an electric lamp is formed by the luminaire and the actual light source (the bulb or the fluorescent tube, etc.); The present invention relates strictly to the fluorescent tube.

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The fluorescent tube, itself known, consists of a glass pipe which is deposited on the siding (inner face) of a fluorescent substance (or a mixture of fluorescent substances) in the form of a very fine powder adherent layer. The pipe is closed at the ends, by welding, with glass caps, through which the metal legs pass, which hold, by tightening, the filaments (each end of the tube having two legs and a single filament).

The center of the glass lid is provided with a central bushing, provided with a thin glass tube, which communicates with the outside, a thin tube which is closed, hot, after the tube has been emptied, generally 0.1 mm col. Hg (~ 130N / m ² ) and the introduction of small quantities of gases such as argon, neon, krypton etc.

The ends of the tube are provided with classic electrical connection sockets, so that the two legs that come out of the glass are made of tubular metallic pins, intended to electrically couple the tube and which pass through an electrical insulating material, contained in a metal ring, asserted on the end of the tube.

Some fluorescent tubes are provided inside the filaments with some metal caps or metal bands that do not touch the filament and have several roles: retaining secondary electrons, controlling the thermal dissipation, etc.

The fluorescent tube works in the nominal lighting regime, by stabilizing an electrical discharge in the gas environment (rarefied and conditioned gas), generally composed of mercury vapor and argon or krypton, for example, brought to the required ionization degree, by using electrons. thermals emitted by the filament at the initial heating stage, electrons which are subsequently accelerated and secondary electrons are produced, by colliding with the mercury atoms (Hg). Mercury atoms produce ultraviolet radiation throughout the discharged environment, and the luminophore layer deposited on the glass pipe transforms the incidence of ultraviolet radiation into radiation with frequency in the visible spectrum; In general, the incidence radiation (spectral line) has a wavelength of 2537A and represents about 60% of the field of spectral lines produced.

The gas environment of the fluorescent tube has a certain resistivity [Ω · mm ² / m], in a cold state and another resistivity, during operation - in general - lower. Due to the negative operating characteristics of the fluorescent tube - with reference to the environment subjected to electric discharge, there is a tendency to increase the intensity of the electric current and decrease the electrical resistance [Ω],

The electric discharge is stabilized by limiting the current (amperage) on the electrical supply circuit, by an inductive or capacitive ballast. The electrical resistance [Ω] of the gas-gas environment for a given length is greater as the cross-section of the gas column is smaller.

This description of the operation of the fluorescent tube is made for a first approximation of the phenomenon, it being much more complex and is not required to explain the operation of the fluorescent tube of the present invention.

R0119397 Β1 in a stable, fluorescent tube; the gas-dynamic environment subjected to electric shock is, in fact, a cylindrical volume of gases (volume comparable to the volume of the glass pipe) that emits throughout its mass and throughout its volume - an ultraviolet radiation, with a yield of about 60%.

It converts into visible radiation by the luminophore, only the ultraviolet radiation front that reaches the luminophore, without the need for ultraviolet radiation produced in the rest of the gas volume.

The ultraviolet radiation front, which touches the luminophore, is practically a cylindrical crown, with a very thin wall.

It is found that the useful part of the volume of gas subjected to electric discharge may be 60 represented by a thin-walled cylindrical crown, not requiring the entire cylindrical volume of the present gas column, consequently the electrical power required to ionize the entire cylindrical volume. tube gas is greater than the electrical power required to ionize only a cylindrical gas crown of the tube.

Basically, the ratio of electrical powers is directly proportional to the ratio of the volumes of 65 gases subjected to electric shock, and the ratio of their electrical resistances (or impedances) is inversely proportional to the ratio of the cross-sectional areas.

In conclusion, the present fluorescent tubes have the disadvantage that they maintain an electrical discharge of a certain electrical power for a cylindrical volume of gas contained in a given tube, instead of an electrical discharge with a smaller electrical power, for a volume of 70 rpm. gas cylinder contained in the same tube (equal in length and outer diameter); this disadvantage is mainly due to the constructive solution of the current fluorescent tubes, which do not allow an electrical discharge, except in a cylindrical gas column, or more precisely in the entire volume of a gas column and not on the volume boundary (independently of the planar shape of the cross-section - currently the disk and of the rectilinear form 75 or curve of the longitudinal geometric axis of the column).

The technical problem, which the invention solves, is to achieve a stable electric discharge on a thin boundary of gas subject to discharge and located in the immediate vicinity of the luminophore, without entraining the rest of the volume of gas (the gas-dynamic environment of the tube) at electric discharge. . 80

The invention solves the technical problem, in that it separates inside the fluorescent tube the cylindrical gas crown subjected to electric discharge - as a thin layer - from the rest of the remaining cylindrical volume that will not participate in the electric discharge, by installing, inside, an insulating pipe closed at ends and concentric with a classic outer pipe, so that between them a cylindrical crown will be defined that will contain the gas subjected to stable electric discharge.

The inner pipe (inner tube) represents the boundary of a volume that does not participate in the electric discharge.

The insulated and drained inner tube, in general, has a very high electrical resistance of its own and can be considered negligible from the point of view of the phenomenology of the electric discharge in the gasodynamic environment of cylindrical crown type, negligible and from the point of view of the electrical parameters, required by the classic electrical installation of the fluorescent tube, classic tube or according to the invention. The installation, in fact classic and known, will be adapted as electric power at lower nominal currents, because the fluorescent tube, according to the invention, operates at a lower power than the one required by the equivalent classical fluorescent tube 95 as geometrical dimensions and lighting performances. The reduction of the electrical power at the terminals of the fluorescent tube, according to the invention, compared to a classical equivalent tube (as size and lighting) comes from the reduction of the gasodynamic volume and not of the specific electrical power, which remains the same imitative 0.05 W / 1cm ³ ).

RO 119397 Β1

The invention has a number of advantages.

Significantly reduces the electrical power required for the ignition and operation of a given fluorescent tube, maintaining the same illumination as flux, brightness, etc., with the current fluorescent tube, equivalent as geometrical dimensions and illumination.

It offers a range of fluorescent tubes, with many economical steps, at the same length, diameter and illumination as the classic ones.

It opens up another perspective to ignition schemes and installations, especially when for long and very economical tubes the required current decreases and the ignition and operating voltage increases; (more widespread use of low power electronic ballasts, etc.) It allows to approach new technologies and materials that could not yet be used, due to the mass production constants that kept the current construction solution consolidated.

It generally reduces the specific mass consumption of tungsten (W), mercury (Hg) and noble gases for most of the manufacturing ranges.

It can allow the creation of fluorescent tubes with larger diameters of the glass pipe, offering greater illumination, at the same electrical power, required for a classic tube of the same length.

It offers the prospect of successive and branched upgrades in the field of fluorescent tubes and fluorescent electric lighting.

The following are some examples of embodiments of the invention in connection with FIG. 1 ... 17 which represents:

FIG. 1, perspective view, with partial rupture, of the fluorescent tube, in a simple constructive variant;

- fig. 2, section and partial rupture through a fluorescent tube, in another constructive solution;

- Fig. 3, perspective view, with partial rupture of a piece of filament;

FIG. 4 is a perspective view of a piece of filament in another embodiment;

- Fig. 5, partial section through a vacuum tube, of this constructive solution;

- fig.6, a view of a thin metal support, supporting and securing filaments or filament segments;

- Fig. 7, view of a mechanical-electrical contact node, for filament segments;

- fig.8, view, rupture and partial section of the fluorescent tube in another constructive variant;

- Fig. 9, view of a nearly circular filament, mounted on a filament piece;

FIG. 10 is a perspective view of a pair of metal mesh screens for protection around the filament;

- Fig. 11, partial view of a grid area, which favors the installation of a mercury capillary capillary;

FIG. 12, partial view, partial rupture and section of the fluorescent tube, in a robust and reliable constructive variant;

FIG. 13 is a view of a group of filament segments mounted on a filament;

FIG. 14, view of a completely circular filament, mounted on a filament;

- fig.15, partial view, in perspective, with sections in the end zone of a fluorescent tube, in the robust and reliable construction version;

FIG. 16, section limited only to one end of a fluorescent tube, with a constructive solution, in which the ignition and operation layer is practically very small (epitaxial), representing the variant with minimized electrical powers;

- fig.17, a view of a filament located without other supports, in a circular channel on the filament piece, for the constructive solution of the fluorescent tube with very low ignition and functioning layer (epitaxial).

In the first embodiment of the invention, in connection with FIG. 1, the fluorescent tube consists of a classic 1 glass tube, used in the current fluorescent tubes, provided, therefore, with an adherent layer of luminophore on the soffit, closed at the ends and equipped at each end with a classical filament and the two classic terminals (pins) required for the power supply of the filament and an inner pipe 2 located concentric with pipe 1, pipe 2 being of electrically insulating material, usually glass, closed at the ends and drained, being smaller in June 155 groans than pipe 1, to be at a convenient distance from filaments and is suspended and positioned without play, inside pipe 1, by means of 3 thin metal supports (wires), recessed at the ends of pipe 2, supports 3 in number of three - four pieces for each end are positioned at 120 ° or 90 ° on the circular contour of the end of pipe 2; they are bent at the ends towards the axis of pipe 2 so as not to scratch the luminophore on pipe 1, during the concentric installation and installation in pipe 1.

The space (volume) between pipe 1 and pipe 2 contains the conventional gas-dynamic environment of a fluorescent tube (mercury, argon, krypton vapors, etc., at a pressure of approximately 130 N / m ² , equivalent to 0.1 mm col.Hg or 0.1 towers).

The inner volume of the pipe 2, emptied or filled (for example, the expanded glass bar with 165 smooth surface on the outside, autoclaved cellular concrete bar reinforced with fiberglass and externally plated with Teflon foil etc.), does not participate in the gas environment. subjected to the electrical discharge of initiation and operation; unloading, electric initiation is also known as ignition (ignition); practically the pipe 2 and the inner volume of pipe 2 can allow a significant leakage of electrical power. 170

The gasodynamic volume capable of generating ultraviolet radiation converted into visible radiation by luminophore is given by the coronary cylindrical space between pipes 1 and 2 summed with the one configured next to the filaments. In this way, the useful volume of operation is smaller than the interior volume of a classic fluorescent tube and of the same dimensions and lighting performances, which translates, practically, by reducing the necessary electrical power. 175

The ignition voltage at such a fluorescent tube is reduced slightly, due to the electrode 3 supports and shortens the length of electric discharge, which is currently equal to the distance between the filaments and now becomes the distance between the inner ends of the 3 electrons. used is generally alternative, but can be continuous. 180

The second embodiment of the invention is also related to FIG. 2 ... 7, in which the aim was to reduce the volume due to the filaments, the use of ceramic parts and a better charge with thermal electrons of the cylindrical coronary space between pipes 1 and 2. On pipe 2, a cap is welded at the ends 4 glass, provided with a vacuum pipe 5 whose interior communicates, through holes a and b, with the inside of pipe 2 and respectively with the outside of pipe 2 which 185 will become the inside of pipe 1; one of the drain pipes 5 has only the hole b.

The ends of the pipe 1 are closed with ceramic pieces 6 in which some thin metal supports 7 are recessed, which have the role of catching and supporting a filament 8 and some metallic conductors 9 which provide the supply of the filament 8 with electric current.

The metallic conductors 9 are connected to some metallic pins 10 which represent, for each 190 ends of the fluorescent tube, two classical power supply terminals, known per se.

The ceramic piece 6 has a central hole c which has the role of gripping and centering the drain pipe 5 in solidarity with the pipe 2.

The drain pipe 5 is of a more robust construction, with diameter steps, is, 195 rule, also made of glass, calibrated as diameter and can be metallized with a layer d to ensure, through an adhesive, a good seal on the hole central c.

RO 119397 Β1

The supports 7 are Y-forked at one end, for filament clamps, and the other free end is embedded in the ceramic piece 6.

A construction of a support 7 is that of an initially U-shaped bent conductor and twisted on the 50% portion until the free ends will be bent in the Y-shape.

The bifurcated parts (ends) are bent at the ends and are intended to provide the necessary tightening and electrical contact with the ends of the filament 8 or filament segments 8 _of which the entire filament 8 is composed.

The filament segments 8 _a can be mounted either in parallel or parallel to the wire 9 for power supply. By this assembly of the filament segments 8 _a , a good formation and support of a filament 8 of the most circular form is ensured; in parts can replace a segment of filament ₈ with a metal conductor 11 connecting the other segments filament ₈ conductors 11 having value only connection between the supports 7, for mounting series and parallel segments filament 8 _a .

The assembly on the pipe 1 (equipped with luminophore) of the ceramic parts 6 already equipped with the filament 8 is made mechanically by precision adjustment (the pipe being bore) and is sealed by adhesives.

In the order of installation, pipe 1 with a ceramic part 6 is fitted and closed at one end; Pipe 2 is inserted until the suction tube 5 enters and is centered on the central hole c prepared with adhesive.

The volume between pipe 1 and 2 is conditioned by the introduction of small quantities of liquid mercury; noting that this sequence is not necessary if one uses the classic formula for attaching a glass capillary with mercury to the filament area.

The other end of pipe 1 is closed with a ceramic piece 6; drain the assembly through the drain pipes 5 and condition it with inert gas (argon, krypton, for example), then close the vacuum tubes 5.

At the ends, insulation plates 12 are mounted on which the metal pins 10 of tubular construction are fastened and through which the connections represented by the conductors 9 pass; heat-bonded metal alloy conductors 9 of metal pins 10. Assert a metal ring 13 around the ceramic piece 6 together with the end of pipe 1 and the insulating plate 12.

At ignition, only the gas environment between pipe 1 and 2 and in the area of the filaments 8 works.

Although the orifice communicates through orifice b and with the interior of the space between pipes 1 and 2, the inner volume of pipe 2 does not participate in significant electrical discharge, because the value of the electric current intensity, near the orifice is less than 1mA and is insufficient to achieve an electric discharge in the volume of pipe 2, the hole a and b has a maximum diameter of 1 * 1.5 mm; provided that the holes (the hole) a is closed with a thermal handle inserted in the drain pipe 5, after emptying and without being disconnected from the vacuum machine, then the inner volume of the pipe 2 will not contain discharge gas and is eliminated any leakage of current inside the pipe 2.

The ceramic part 6 can be made of special heat-resistant glass and especially with small coefficients of thermal expansion.

Another embodiment (third) of the invention in connection with FIG. 8 ... 11 is given for a constructive solution, in which the space around the filaments has been further reduced and the full use of the glass is ensured as the basic material; the filament has a circular arrangement and there are mounted protective grids around the filament.

Pipes 1 and 2 are fixed to a glass frame 14 equipped with filament segments 8 _a and metallic conductors 9, but also with the drain pipe 5 provided with hole a and b.

RO 119397 Β1

The glass frame 14 is provided with some bumps necessary for the mounting of the supports 245 1 and the conductors 9; the swellings are classic and used, for example, in the electronic tubes for the wires for connection with the electrodes inside.

Around the frame 14, there are placed some metallic protective grids 15 and 16 of truncated wire mesh shapes that have some cuts f around the bumps e so as not to touch the supports 7 and the conductors 9. 250

The metal grates 15 and 16 are semi-finished and do not close completely, having a clearance zone g.

In the clearance zone g, a thin metallic conductor 17 wrapped on a capillary 18 with mercury can be connected to the grid 16; actually used in some of the current fluorescent tubes. 255

Conditioning, including emptying of the gas environment between pipes 1 and 2 is done through the drain tube 5, which is then thermally closed.

The fluorescent tube is closed, at the ends, in a classic way: the insulating plate 12 with metal pins 10 and the metal ring 13.

Pipe 1, obviously, is treated on the soffit by forming the adherent layer of 260 luminophores. The outer grid 16 is mounted after the filament segments 8 _have been assembled.

If no electrical contact is desired between the halves of each of the 15 and 16 grids, they will immobilize each other with glass droplets, for example.

In principle, grids 15 and 16 should not be short-circuited (so there is no metal contact between them); also, none of the gills 265 15 and 16 are closed in the short circuit, except when the capillary with mercury 18 is required to be caught by the conductor 17, which is precisely the role of heating mercury and even of heating. capillary crack 18 (in the constructive version with capillary, which contains mercury and is closed).

Another embodiment of the invention (fourth), in connection with FIG. 12 .... 15, is the constructive solution, in which the robustness and reduction of the thickness of the 270 gas-dynamic ignition and operation layer between pipes 1 and 2 are addressed.

between the pipes 1 and 2, there is at the ends a glass mount 19, each provided with two drain pipes 5, two holes a and one hole b; one drain tube 5 has two holes a and b, and the other drain tube 5 has a single hole a.

The mount glass 19 is initially formed in three parts 19 _a, 19 _b and 19 _c which is subsequently hot-deaza SU 275; mount 19 is shaped like a cylindrical pipe.

Pipe 2 is fixed, cold, with adhesives on the glass mounts 19 _a , and emptied, then the drain tubes 5 are closed. A ceramic part 20 is mounted on mount 19 _b . The ceramic part 20 supports the mounting of the grids 15 and 16 through some metallic conductors 21 and the filament 8 through some metal filament brackets 22. Only two of the metal filament supports 22 280 communicate electrically with the metal pins 10 through conductors 9; the ceramic part 20 is concave profiled through the clearance zone g next to the filament 8.

Filament 8 of circular shape, is composed of filament segments 8 _a ; in FIG. 13 there is a mounting with filament segments 8 _of mounted in series and in series, and in fig. 2:01 p.m. segment filament assembly ₈ connected in parallel. 285 in order of installation, the pipe 2 of mount 19 _a is sealed; the mount 1% with the filaments 8 and the conductors 9 of electricity supply; drain pipe 1 and close two of the corresponding drain pipes 5; weld 19 _b , mount 19 _a ; a ceramic piece 20 equipped with grids 15 and 16 is introduced; position pipe 1 over pipe 2 until the contact is included on the ceramic part 20; welds 290 [

19 _c of pipe 1 and of the mounts 19 _b . At the other end of pipe 1, everything is mounted the same, having

RO 119397 Β1 takes care of the mercury conditioning of the volume between pipes 1 and 2; then vacuuming (or vice versa vacuuming and conditioning with mercury), conditioning with an inert gas and hot closing the other two vacuum tubes 5. The fluorescent tube ends by inserting the insulating plate 12, bonding the metal conductors 9 to the metal pins 10 and asserting the ring metallic 13.

In order to prevent accidental rotation permanently, during the operation of the insulating plate 12 of mount 19 _C , there are provided the holes h, on plate 12 and the projections i, on mount 19 _c all the claims will use adhesives, frits, etc. in areas supporting mechanical seals or clamps. Pipe 1 has luminophore on the soffit.

A last embodiment of the invention in connection with FIG. 16 and 17 refer to a constructive solution in which the gas-dynamic ignition layer is practically thin (epitaxial), offering the most economical fluorescent tubes; have a circular filament furnace unsupported by metallic components and use precision processed ceramic components; at the same time, the strength of the tube and its reliability were sought.

Pipe 1 and pipe 2 are fixed and closed, at the ends, with some ceramic mounts 23; pipe 1 is in contact, on the soffit, with an adherent layer of luminophore.

A frame 23 is composed of two circular pieces 23 _a and 23 _b , which are sealed on a truncated area j and define a circular channel 24 with a semicircular section, provided with an annular slot k.

The circular piece 23 _a , shaped like a ring, has a threshold and subdiameter, to enter the inside of pipe 1 and to ensure the sealing.

The circular piece 23 _b has a conical discoidal shape, provided centrally with a drain pipe 5, with a hole a and provided, peripherally, with a threshold m entering the pipe 2. Through the circular piece 23 _b, the metal conductors 9 pass through and out. power supply of the filament 8 disposed in the circular channel 24.

J truncated cone-shaped area may be metallized for each of the mounts 23 _a and 23 _b in order to ensure good sealing or by adhesive or by laser welding.

in order of installation, the filaments 8 are mounted in the channel 24 formed by parts 23a and 23b and the area j is sealed, finally obtaining two mounts 23. At the end, the two pipes 1 and 2 are fixed with a mount 23; the quantity of mercury is introduced into the space between pipes 1 and 2; the two pipes 1 and 2 are closed at the other end with the other mount 23.

$ io another solution for mounting is possible, in view of the fact that the grommet 23 is formed of pieces 23 _a and 23 _b by closing the first, the pipe 2 parts 23T, and subsequently the pipe 1 with the parts ₂₃ being closed by soldering or welding of the common area j. All seating and sealing surfaces will be treated with adhesive for good sealing.

The quantity of mercury is introduced, the assembly is emptied through the drain pipes 5 and conditioned with inert gas, then the hot pipes 5 are closed; mercury conditioning can also occur after emptying.

Close the tube at the ends, with the insulation plate 12, attach the wires 9 to the power supply to the metal pins 10 and assert the assembly with the metal ring 13.

Pipe 2 can be reduced in diameter, at the ends, in the clamping area on parts 23 _b , in order to ensure that the thickness of the gas-dynamic layer between pipes 1 and 2 is maintained at the same thickness as the slit k. The electric power supply wires 9 will be externally insulated on the free portion until contact with the metal pins 10.

All the embodiments of the invention allow the mounting on the wall of pipe 1, at the ends, of auxiliary ignition electrodes - not shown - electrodes currently used in some fluorescent tubes.

Claims (5)

claims 1. Fluorescent tube, characterized in that the gas-dynamic environment subjected to electric discharge 340 is located between two concentric pipes, an external pipe (1) and an inner pipe (2), the outer pipe (1) being glass, usually transparent. , and has an adherent layer of luminophore deposited on the soffit, and the pipe (2) is made of glass or other electrically insulating material, the two pipes (1 and 2) being closed, at the ends, where some filaments (8) are placed or in place. them, some ignition electrodes, some metallic conductors (9), the position of the tab - 345 of the menu (8) being next to the cylindrical coronary volume between the pipes (1 and 2), the pipe (2), drained inside, in general, and by suitable length is suspended in a concentric position with respect to the pipe (1) either through some thin metal supports (3) or through end pieces (4, 6, 14, 19, 23), depending on the constructive solution chosen. 2. Fluorescent tube, according to claim 1, characterized in that the inner volume of the pipe (2) does not contain electrodes or filaments and therefore does not participate in the electric discharge required for the illumination produced by the fluorescent tube, and the volume of the pipe (2). it is significantly close to the volume of the pipe (1), and in some cases it is very close. Fluorescent tube, according to claims 1 and 2, characterized in that the tube (2) can be replaced, in whole or in part, with an electrically insulating cylindrical part of the same volume 355 and with a full core. 4. Fluorescent tube according to claims 1..3, characterized in that it can also use protective grids (15, 16) of the filament (8), the grids (15, 16) being made of metal mesh and do not touch the filament ( 8). 5. Fluorescent tube according to claims 1 ... 4, characterized in that the 360 filaments (8) or filament segments (8 _a ) are adapted to the new reduced electrical power required, and the alternating current electrical installation, in general, of ignition and operation in stable nominal regime, is suitably sized, for lower intensities of the electric current, with changes of the working frequency or of the ignition voltage required where appropriate and, especially, for the constructive solutions where the impedance of the gas environment is 365 higher both in cold, during non-operation and hot, during ignition and operation, compared to the current values used, the constructive solutions with increased cold resistance of the gas-dynamic environment being those with epitaxial gas-dynamic layer and which correspond to the fluorescent tubes, which requires the lowest electrical power required to produce illumination identical to a classic fluorescent tube, equivalent as geometric surface and 370 meters of illumination.