WO2008072990A1

WO2008072990A1 - Fluorescent light emission structure and application of this structure to fluorescent lamps production

Info

Publication number: WO2008072990A1
Application number: PCT/RO2007/000026
Authority: WO
Inventors: G. Ion Nemes
Original assignee: Nemes G Ion
Priority date: 2006-12-15
Filing date: 2007-12-14
Publication date: 2008-06-19
Also published as: WO2008072990B1

Abstract

This invention refers to a high efficient fluorescent light emission structure, having a large emissive surface, using an electric discharge inside a low pressure noble gases and mercury enclosure. and application of this structure to produce fluorescent lamps for domestic, industrial and public lighting or for LCD screens any shape or size. The problem to be solved: to enhance the efficiency of the light structures; Solution : is done by the small cross-section of the electric discharge and the great surface of the exposed fluorescent material. The light emitting structure uses as electric discharging space the vacuumed, communicative pores, holes and interstices among a grained, glassy, transparent layer coated with/or containing fluorescent material inside an air-tide enclosure sealed between thin, glassy, transparent sheets covered with/ or containing fluorescent material. The thickness of the porous, grained layer is kept by some protuberances, ribs, nervures or undulations of the external sheets or by the porous, grained middle layer itself. A fluorescent lamp using such a structure is made by external glass (12) sheets, having some (13) protuberances or nervures, coated with/or containing fluorescent (14) material, sealing the vacuumed, porous, middle (15) layer made by glass fibers or grains coated with/or containing fluorescent material Some cold (16) electrodes are made by wire, tin or vacuum deposed metal. A reflective (20) layer.is deposed on the back of the rear sheet.

Description

FLUORESCENT LIGHT EMISSION STRUCTURE AND APPLICATION OF THIS STRUCTURE TO FLUORESCENT LAMPS PRODUCTION

This invention refers to a high efficiency fluorescent emission structure having a large emission surface, using an electric discharge in mercury vapors at low pressure, with applications to produce lamps for: domestic, industrial and public lighting or for LCD screens of any shape or size.

There are already known many other light sources based on the UV-radiation acting on fluorescent surfaces, like the plan lamp described in the RO120565 Patent, where the low pressure volume enclosed between two phosphor coated glass plates is the space where the electric discharge and the UV-emission is produced. The glass plates have about 5mm in thickness and the distance between the glass plates is about δmm.The plan lamp is 110mm broad and this width is strong limited by the reason to resist against the atmospheric air pressure.

The main disadvantages of this solution are:

-a large cross-section of the plasma inside the lamp with a consequent energy consumption;

-a heavy lamp embodiment due to the thickness of the glass plates and

-a reduced lighting efficiency due to the small phosphor surfaces.

There is also known a double tube fluorescent lamp as well described in JP 11191385 that comprises two concentric phosphor coated glass tubes which form a gap between themselves where an electric discharge is produced. The plasma cross-section is high and the phosphor surface is also limited reducing the performance of this kind of lamp.

The light emitting structure, according to this invention, removes those disadvantages, reducing the cross-section of the UV generator could plasma using as a low pressure electric discharge volume a communicable porous space existing among small, micro or macroscopic glass or glass like made corpuscles of any geometric or irregular shape or size, or, using as such low pressure discharge volume some communicable micro or macro gaps any shape or size performed inside a glass or a glass like body during the production process, the fluorescent material being mainly distributed on the surfaces of glass corpuscles or gaps or included in the mass of the glass or glass like corpuscles, sheets or body. In one embodiment of a such light emitting structure the emission of the light in the visible spectrum takes place by the excitation with a UV radiation of the fluorescent fine particles adherent to the multiple micro and macroscopic existent corpuscles, pores or gapes lateral surfaces or in the corpuscles mass themselves of any geometric or irregular shape and size as foils, powders , granules and/or like foil forms, spheres, sticks, cubes, or packet filament agglomerations type, wad or fibers glass felted or other similar dinkered minerals as well as thermo resistant and transparent glazes and varnishes, or on the voids surfaces, interstices, communicating pores or capillary micro tube of any section and size - indifferent, parallel, secant or tangent existent into an alveolar, cavernous, porous, transparent layer, by the same kind with glass, building a low pressure, bounded enclosure, by some tight and transparent surfaces or by transparent plaques, quasi-parallel, large-sized versus their distance, plane or curved, with protuberances or all kind of nervures (form and dimension) serving as a light guide and plane stiffening, covered themselves with adherent fluorescent substance or containing it, the vacuum enclosure being lateral delimitated by sealing edges, the low pressure UV radiation being produced by the electric discharge between at least two electrodes or filament-electrodes in the vacuum or rarefied noble gas by excitation of the atoms of gas, mercury, sodium, halogens, etc, the could plasma so produced in the communicable canals and pores excites the fluorescent stuff producing visible light. The fluorescent material is the real producer of the visible light .A distributed fluorescent material in the mass of the glass body or corpuscles is much more advantageous to avoid the direct contact with the plasma and UV-radiation and conduces to a longer life of structure. The fluorescent and porous material in its pores and gaps is the seat of the plasma development and also the UV generator, but, also, the visible spectrum light emission seat and at the same time could be also the external plaques bearing support which confers the mechanic resistance of the structure. This material with pores and communicating fine canals covered with fluorescent material or containing it could be realized also in monolith structure with the external delimited transparent, porousless, air-tight surfaces. If there is used a porous, amorphous material, without mechanic resistance, as well as glass wed or the glass felted fiber or many granules layer treated with fluorescent material, than the small distanced plaques bearing is increased by nervures or undulations or protuberances of any kind of plaques or by distinct corps like granules, rods, tubes, any kind of transparent granules treated with fluorescent material or containing it The beating-up material degree is the factor that induces the material porosity, cross-section surface respectively plasma volume, with the direct influence on the electric discharge intensity and on the energy economy, respectively on the fluorescent material total exposure surface with influence on the source luminance, finally on Im/W factor. The defining structure of a light emitting surface unit realized according the invention is a thin sandwich or wafer composed by two external quasi-parallel glassy sheets of any form, dosed tight on the contour, transparent at visible light and UV radiation, resistant and tight at pressure differences between interior vacuum and the atmosphere, contained a glassy, porous, holed material, with communicating, vacuumed gaps, as well as the glass wad or the glass felted fiber covered by fluorescent material or containing itself. The porous material transparent at UV radiation and at visible light, is the seat for an electric discharge UV generator between any electrode or electrode-filaments. If the front cover sheet is UV transparent, an UV filter layer is foreseen to protect the ambient

The external plaques, transparent at visible light are kept on the specified small distance by any nervures or protuberances of any kind of shapes which could be a part of the plaque structure oneself, accrued, from these or being independent corps, of any form and wished thickness, transparent, covered by fluorescent material or containing it and performing the following charges:

- to increase of fluorescent material exposure surface to UV radiations;

- to keep the distance between transparent plaques treated with or containing fluorescent material during the vacuum process and the lamp exploitation;

- to conduce the light toward exterior(light guide)

- to improve the structure rigidity .

The transit from the tight, transparent exterior surfaces to the interior porous material with communicant vacuumed voids in which take place electric discharge, UV radiation production and fluorescent material excitation can be made by separation nervure surfaces covered by fluorescent material when a compound of different layers is used or gradual in the case of the solid, homogeny fabrication technology.

If the light emission is needed only by one side of the lamp faces, as well as the plane or gently curved lamps case installed on ceiling, on walls, on floors or behind LCD screens or in case of great volume forms like polyhedral, cylinder, spheres, ovoid shapes the rear side of the back/inner walls are treated with reflective materials by aluminizing or other procedures with similar effects.

The main technical problems which this invention solves are the increase of fluorescent material exposure surface to UV radiation, the plasma cross-section reduction with consequent energy consumption and reducing the weight of the lamp by some light and thin materials. The applications of this light emitting structure to produce lamps leads on following advantages:

- a great diminution of plasma cross-section with great impact on energy need;

- a significant increase of exposed fluorescent material surface;

- a small weight and an augment of mechanic resistance structure;

- an increase of energetic efficiency, as the effect of the first and second items.

In succession we give many examples for the performance of the light generating structure in conjunction with the figures 1-16 representing:

- fig. 1 - cross- section and perspective of a light emitting structure, surface unit ; ,sandwich type, generic defined; ?

- fig. 2 - cross- section and perspective of a light structure surface unit one-piece type;

- fig. 3 - perspective drawing and partial cross-section of a plane or easy curved flat lamp;

- fig. 4 - cross-section and perspective of a capillary tubes and/or sticks type structure;

- fig. 5 - cross-section and perspective of a drilled balls type structure;

- fig. 6 - cross-section and perspective of an orthogonal cylinders type structure;

- fig. 7 - cross-section and perspective of a cuboids type structure;

- fig. 8 - cross-section and perspective of a prisms type structure;

- fig. 9 - cross-section and perspective of a pyramids and cons structure;

- fig.10 - cross-section and perspective of an undulated foils type structure;

- fig.11 - cross-section and perspective of a folded or goffered type structure;

- fig.12 - cross-section and perspective of a honeycomb type structure;

- fig.13 - cross-section and perspective of a buffles type structure;

- fig.14 - cross-section and perspective of overlapped structures;

- fig.15 - perspective drawing and partial cross-section of a solid lamp;

- fig.16 - perspective drawing and partial cross-section of a cylindrical lamp;

- fig.17 - perspective drawing and partial cross-section of a bulb or spherical lamp;

- fig.18 - perspective drawing and partial cross-section of a lamp with separate UV source.

Generally, a light emitting structure according to this invention, excepting the edges which seal air tight the structure, is composed by a sandwich comprising at least three layers of different features: two exterior layers (1) made by glass or other glasslike materials with similar properties like visible light and UV transparency, covered by fluorescent material on both faces, or better including it, with enough mechanical resistance even at high temperature during the vacuum process, eventually with some protuberances, undulations (2) or ribs between them with the triple role to keep distance between the exterior layers, to improve the exposed surfaces of the fluorescent material and to serve as light guide, and between the two exterior layers ,a third, interior porous material(3) with a high UV and visible light transparency, with communicative pores, gaps and canals painted with/or better containing fluorescent material. The emitting face, if is made by UV transparent glass is to cover with an anti UV filter layer, but if is made by UV opaque glass, no UV filter is to add.

This middle layer is the vacuumed space where the electric discharge takes place and in presence of some noble gases and mercury vapors an UV radiation is produced and acts on the fluorescent material. The middle layer must also be thermo-resistant to bear the high temperature needed by the vacuum process. Using different noble gases and fluorescent materials, the emitted light has different colours. The high efficiency of this kind of lighting structure is based on:

-the decreasing from 1/10 to 1/1000 of the cross-section of the plasma involving a similar decrease of the current intensity and indeed the electricity consumption and -the similar increasing (10-1000 or more) of the exposed surface of the fluorescent material. If single side lamp is needed like ceiling, walls or floor lamps or backlight for LCD screens is required, or a volume lamps like cylindrical, sphere, polyhedral shape is to produce, a reflective (4) layer on the back side of the light emitting structure is provided.

According to this invention is also a solid lighting structure formed by a single (5) layer with different properties areas, e.g. a tight, transparent to the visible light but opaque to the UV, eventually made opaque to UV by an exterior anti UV filter, an exterior (6)area ,a porous(7)area, with communicative (8) gaps painted with/or including the fluorescent material (9) and an other transparent and tight (10) area with a reflecting (ll)layer. The fluorescent material can be included in the (6) and (10) areas but also can be deposed as an external layer on area (6) surface; in this case, the area (6) must be also made be an UV transparent material like the middle area (7) itself and protected by an other layer transparent to the light but opaque to UV.

An embodiment of a lamp based on the light emitting structure comprises some thin glass (12) plaques having ribs or protuberances (!3) and treated or containing fluorescent (14) material inside the mass, these ribs or protuberanoes having the role to maintain the mm-range average distance between the two plaques during the vacuum process and the exploitation, the glass (15) fibers painted with /or containing fluorescent material are pressed between the plaques. The metallic (16) electrodes are made by wire, tin or vacuum deposed metal always on antipodal sides of the lamp sealed by some (17) laps in the melted glass during the lamp welding. Some hot filaments (18), antipodal mounted, representing just 1/10 to 1/100 of the electrodes length can help the ignition. If the electrodes are supplied with high voltage over 400 V produced by a chopper device, the hot filaments are not used. A capillary tube (19) well- known from the fluorescent lamps technology is provided to serve the vacuum process, the noble gas and mercury injection after the vacuum process and will be sealed after that The reflective (20) layer obtained by aluminizing is provided on the backside of the lamp to improve the light efficiency of the active face.

The thickness of the glass sheets, in connection with the lamp size is between 0.1 and 10mm (for large, meters sized, advertising panels) but usually do not exceed lmm.The porous, middle layer is about lmm thick and surface of such a lamp is from few cm2. for digital cameras and camcorders to many m2. or more for large displays.

In other variants of embodiment, the fiber glass middle layer can be replaced by some capillary (21) pipes and tubes, thin (22) baguettes or sticks, drilled (23) balls, cylinder (24) ,cubic (25),prismatic(26) , pyramidal (27)shaped granules, undulated (28),folded (29) goffered (30) foils, undulated (31) bands, baffled (32)strips and blades (33) or any other available grains and porous structures made of a glassy, or glass like material ,e.g. quartz or silica, visible and UV light transparent, thermal and mechanic resistant, treated or containing fluorescent material, having a granularity of 0.01 to 10.0 mm and a convenient communicative gaps density to assure the electric discharge and the stable could plasma forming with UV energy radiation and the optimal fluorescent material excitation. It is obviously not recommended to use a single layer of gross equal sized granules to bear directly the vacuum low pressure and to assure the porous space for the could plasma and exposing surface for the fluorescent material by itself too, because without smaller sized grains, the gaps volume is to high and the exposed fluorescent material surface is to small .A mixture of great granules of lmm with other smaller e.g. about 0.33mm, 0.11mm and 0.04mm and so farer is working properly if the amount of great granules which play the role of spacing means do not exceed 1-10% of the mixture content To avoid the burning of the fluorescent material is recommended the mixing of the fluorescent material in the mass of granules, foils ,fibers etc., of the porous middle layer but in the external glass sheets too. A combination of any form and size of structures like those already described or of other shapes not presented, but similar, is possible in the same frame of this invention, inclusive a stack made of unitary (34) structures, the middle (35) layer being obviously UV and light transparent.

A special solid structure is obtained using a single glass (36) plaque having made, in melted stadium during the manufacturing, some communicative canals (37), equal or different aperture, shapes and sizes, parallel, tangent, secant, treated with fluorescent material or better containing it ,the end edges being sealed by some (38) baguettes already containing the electrodes (39) on their generating line.

A true embodiment of a cylindrical, bulb or spherical lamp, according to this invention can be made, if is talking about very small power, equivalent to the LED lights, or neon micro lamps, by filling the entire volume of the bulb with glassy granular, containing fluorescent material, stuff. For large sized cylindrical lamps, between the ribbed (41) and (42) walls, treated with, or containing fluorescent material, a porous, granular or fiber kind ,glassy ,treated or containing fluorescent material is pressed ,vacuumed and sealed, a reflective (43) layer on the rear of the interior wall being provided. The electrodes (44) not represented an (45) having circular shape are made by wires, metallic tin or vacuum deposed alike of the planar lamps, having some small warm filaments type (P) and (f) antipodal mounted. An other configuration of electrodes is also possible if desired, like linear (46) and (47) opposite on generating lines mounted, or spiral shaped, but always with warm filaments (f) and (f) antipodal mounted. Large sized bulb and spherical lamps, according to this invention, have two ribbed thin glass walls, containing between them a porous,(48) glassy, treated or containing fluorescent material, the inner (49) wall being treated (50) or containing fluorescent material and a reflective (51) layer on the rear, the outer wall (52) being treated or containing just fluorescent material. The central top electrode (53) cool type, is supplied with electricity by the wire (54) from the electronic chopper (55) mounted in the lamp base, the circular (56) electrode wire made, or vacuum deposed, containing a small filament (57), is mounted on the base end of the bulb. An other embodiment of the porous light emitting structure, according to this invention, comprising an outer glass (58) enclosure plane, curved, cylindrical or bulb shape manufactured, containing inside a low or high pressure gas e.g. argon, an UV generator (60) and a porous, granular or fibred, glassy (61) layer treated or containing fluorescent material deposed on a transparent or between two transparent glassy sheets. The UV generator itself is made by two concentric quartz tubes (62) and (63),a reflective layer(64) being deposed on the inner side of

Claims

C L A I M S

1) Light emitting structure useful to fluorescent lamps production, based on stimulation of fluorescent material by UV radiation produced by an electric discharge inside of a mercury vapours and noble gases low pressure enclosure, according to this invention, characterized by that, the low pressured mercury vapours and noble gases enclosure where the electric discharge generates UV radiation is a porous, with communicative gaps and holes space among vitreous grains of any shape and size coated or/and containing fluorescent material, this porous middle layer or area being air tide enclosed at least by one single tide envelope wall or surface, or more external, quasi-parallel, plain or curved glassy sheets or surfaces coated or containing fluorescent material, the middle grained, porous, glassy layer or area being made by an UV and visible light transparent , UV stabile, inorganic or organic glass ,but the external visible light transparent sheets or surfaces must contain an UV filter or be coated with an UV opaque layer, the clearance between the two external sheets being kept during the vacuum procedure and the exploitation by some ribs, protuberances or undulations of the sheets, or by some grains of the middle layer, or by structure itself in case of solid structure solution, for some applications an outer reflecting layer on the back of the rear sheet being foreseen, such light emitting structure being obviously useful if is included in a lamp body which assure the marginal air tide sealing and electrical discharging connections like electrodes, filaments, pins ,high voltage supply etc.

2) External envelope, plaques or sheets, according to this invention, in connection with the claim nr.1 , characterized by that, are made by glass (1) or glass like materials transparent to the visible light but opaque to UV radiation, or outward coated with an UV opaque filter on the radiant face, having some ribs (2), protuberances, nervures or undulations made with the triple role as fluorescent surface enhancer, light guide and clearance bearer in case of granular, non-positive middle (3) layer, having eventually, a reflective (4) layer on the back side of the rear sheet. 3) Light emitting structure, according to this invention, in connection with the claim nr.1 , characterized by that, is made as a single (5) body, solid glass transparent to UV and visible light structure containing fluorescent material, having different properties areas, like external air tide (6)(10surfaces, the middle (7) porous area with communicative holes, coated with/ or containing fluorescent (8) material, the front face being coated with, not represented, UV filter and the back face with an eventually reflective (11) layer.

4) Fluorescent flat or light curved lamp as described, applying the light emitting structure according to this invention, in connection with the claims nr.1-3, characterized by that, the external thin glass (12) sheets having some (13) protuberances and coated with/or containing fluorescent (14) material in mass, include between them at least a middle (15) porous layer, coated with/or containing fluorescent material able to emit visible light during exposure under UV radiation produced by mercury and noble gases low pressure electric discharge between at least two metallic (16) electrodes made by wire, tin or vacuum deposed metal always on antipodal sides .sealed by some (17) laps in the melted glass during the welding, some eventually hot (18) filaments always antipodal mounted and representing just a small quote of the electrodes length help the ignition. A capillary (19) tube assures the vacuum and the mercury and noble gases injection process being sealed after that. A reflective (20) layer made usually by aluminizing the rear side of the back sheet is provided to enhance the light radiation of the front face of the lamp.

5) Porous material used as middle layer, according to this invention, in connection with the claim nr.1 , characterized by that, is made by a stack, a felt, wad or agglomeration of glass fibers (15), capillary (21) tubes, thin (22) baguettes or sticks, glass or glass like material made, coated with/or containing fluorescent material inside their mass.

6) Porous material used as middle, main layer, according to this invention, in connection with the claim nr.1 , characterized by that, is made by a stack or agglomeration of grains geometric or irregular shape any size made by glass or glass like materials, like quartz or silica, coated with /or containing fluorescent material, e.g. full or drilled (23) balls, cylinders (24), cubic (25), prismatic (26), pyramidal (27) shaped granules or a mix of any shapes and sizes, the big sized elements playing the role to bear the clearance between the external sheets ,but the small sized filling the interstices .reducing the plasma cross-section and enlarging the exposed surface of the fluorescent material.

7) Middle porous layer according to this invention, in connection with the claim nr.1 , characterized by that, is made of some glass undulated (28), folded (29), goffered (30) foils, undulated (31) bands, baffled (32) strips and blades (33), mounted in a single (34) layer or multiple (35) layers stack.

8) Very small power lamps, equivalent to the LEDs or neon microlamps, according to this invention, in connection with the claim nr.1 , characterized by that, the porous, grained, glassy stuff, containing/or coated with fluorescent material, fills the whole space inside a cylindrical, spherical, bulb or any shape low pressure glassy small enclosure delimited by a single, external glass envelope, having at least two opposite, one central and another peripheral or antipodal mounted electrodes.

9) Large size cylindrical fluorescent lamp, applying the described light emitting structure according to this invention, in connection with the claims 1-6, characterized by that, the porous, grained, vacuumed layer, made of/or coated with fluorescent glassy material is pressed between two ribbed (41) and (42) glassy cylindrical walls also coated with/or containing fluorescent material, sealed on their common bases, a reflective (43) layer being deposed on the inner side of the interior wall, the cold, hot, or mixed circular electrodes (44) and (45) being antipodal mounted. In another configuration the linear (46), (47) electrodes can be on antipodal generating lines mounted, with or without some hot (f), (f ) filaments helping the ignition. A spiral shape of the electrodes is also possible.

10) A fluorescent spherical or bulb shaped large size lamp, made as application of the light emitting structure according to this invention, in connection with the claims nr.1 -6, characterized by that, the porous (48) layer glassy, coated with/or containing the fluorescent material is enclosed between the inner (49) wall coated with/or containing fluorescent (50) material having a reflective (51) layer on the interior and the outer (52) wall also coated/or containing fluorescent material. The central top (53) cold type electrode is supplied with electricity by a wire (54) from the electronic (55) mounted e.g. in the lamp base, the secondary, circular (56) electrode wire made or vacuum deposed metal containing eventually a small (57) filament is mounted around the base of the bulb.

11) A fluorescent high pressure lamp, according to this invention, in connection with a part of the claim nr.1, characterized by that, an external glass (58) enclosure, plane, curved, cylindrical or bulb shaped having a porous (61) glassy layer coated with/or containing fluorescent material, filled with a low or high pressure (59) gas, the porous, fluorescent material being exposed to an UV radiation produced by an independent (60) source having two concentric quartz (62), (63) tubes and a reflective (64) layer on the inner side of the inner tube, having two filament (65), (66) electrodes and an ignition (67) electrode too, a parabolic (68) mirror serving to concentrate of the light and UV radiation to the fluorescent porous layer.

12) Electrodes for ignition and electric discharge, according to this invention, characterized by that, are made by wire, metallic tin, or vacuum deposed metal, having usually the shape of the porous discharging layer, being always antipodal mounted and having a small quote of its length made by filament to help the ignition.