MXPA00009384A - External electrode driven discharge lamp - Google Patents

Abstract

A discharge lamp (20), such as a neon lamp, comprising a laminated envelope having a gas-discharge channel and at least one external electrode (44) in communication with the gas-discharge channel (20), the laminated envelope having a front surface (32) and a back surface (28) integrated together to form a unitary envelope body essentially free of any sealing materials. The external electrode (44) comprises an electrode surface integral with the laminated envelope and a conductive medium disposed on the electrode surface. The conductive medium may be conductive tape, conductive ink, conductive coatings, frit with conductive filler or conductive epoxies. The discharge lamp may comprise a laminated envelope including a plurality of separate gas-discharge channels and external electrodes in communication with the gas-discharge channels, whereby the discharge is driven in parallel.

Description

DISCHARGE LAMP DRIVEN BY EXTERNAL ELECTRODES BACKGROUND OF THE INVENTION • FIELD OF THE INVENTION The present invention relates to a low pressure discharge lamp in which external electrodes are used to drive an electric gas discharge formed within a laminated envelope. Plus In particular, the present invention relates to such a discharge lamp that could be used for the purpose of automotive rear-light applications.

DESCRIPTION OF THE PREVIOUS TECHNIQUE 15 In the neon signal industry, the common type of electrode used in low pressure discharge lamps is the internal electrode. The internal electrodes, as the name indicates, are located inside the glass pipe and typically consist of a recessed piece metal coated with emissive coating. A connection is made to an external power source through a wire that is sealed from glass to metal in the pipe. See generally W. Strattman, Neon Techniques, Handbook of Neon Sign and Cold Cathode Lighting, ST Publications, Inc., Cincinnati, Ohio (1997). A significant problem associated with discharge lamps • Low pressure comprising internal electrodes is a reduction of the useful life due to the failure of the electrodes that result in the bombardment of the electrode by gas ions and the electronic deposition of the electrode material. In addition, the failure in these discharge lamps is also associated with leakage in the glass to metal seal, ie in the seal between the glass envelope and the electrode. This mode of failure is particularly true 10 in discharge lamps having borosilicate to tungsten seals. In contrast to the internal electrodes, the activation of an ionizable gas by the external electrodes eliminates the aforementioned destruction of the electrodes, resulting in the longest useful life of the lamp, ie the external electrodes are on the outside of the electrode. glass tubing and are therefore not subject to bombardment by gas ions. The term "external electrodes" is applied to refer to electrodes that are not internal to the glass article containing the ionizable gas. A further feature of driving a discharge through external electrodes is that multiple separate channels 20 can be driven in parallel, as opposed to driving a discharge through internal electrodes, which will follow only the minimum resistance path. - «* j ^ ^^ s * == ^? ¡== ^^^^^^ Capacitive coupling has been exposed to a low pressure discharge, ie the implusion of a discharge through external electrodes f , in the US patent No. 4,266,166 (Proud et al.) And the patent of E.U.A. No. 4,266,167 (Proud et al.). The patent of E.U.A. No. 4,266,166 discloses a fluorescent lamp comprising a pear-shaped glass envelope or an incoming cavity in the lamp housing. An outer and inner conductor, typically a conductive mesh, is disposed on the outer surface of the shell and on the surface of the cavity , incoming, respectively. Similarly, the patent of E.U.A. No. 4,266,167 discloses a fluorescent lamp comprising a pear-shaped glass envelope with an incoming cavity. An outer conductor, typically a conductive mesh, is disposed on the outer surface of the lamp housing, and an inner conductor, typically a solid conductive device, fills the incoming cavity. Both patents expose the use of a high frequency of operation, in the range of 10 MHz to 10 GHz. In the patent of E.U.A. No. 5,289,085 (Godyak et al.), A fluorescent lamp is exposed in which a double tube lamp envelope comprises electrodes at or near the ends thereof for capacitive coupling to a low pressure discharge lamp. Externally located electrodes are exposed which comprise layers or bands of metal at or near the ends of the tube casing. Frequencies are suggested in the range of 3 MHz to 300 MHz.

The patent of E.U.A. No. 5,041, 762 (Hartai) discloses a luminous panel comprising a flat glass envelope formed of two plates Jfe of glass, the flat glass envelope containing a gas discharge channel that forms by machining a groove on the surfaces of the plates. Although the preferred embodiment exhibits internal electrodes, electrodes of the capacitive type are also suggested.

OBJECTS AND ADVANTAGES • An object of the present invention is to provide a discharge lamp for use in automotive backlight applications that have simplicity of packaging, long lifespan, energy efficiency and cost by employing external electrodes to drive a confined electric gas discharge within of a laminated wrap. Another object of the present invention is to optimize the capacitive reactance of the site of the external electrodes by manipulating the geometrical configuration of the electrode with the method of forming the laminated envelope.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, these and other objects and advantages are achieved in a discharge lamp comprising an envelope * - »» ---? - - «-« - * *. * -. »W¡ ** ^. . The laminated and external electrodes to induce an electric gas discharge. The laminated envelope comprises at least one gas discharge channel and an ionizable gas confined within the gas discharge channel. The ionizable gas is activated by external electrodes that are in communication with the gas discharge channel. The external electrodes comprise an electrode surface and a conductive medium on the electrode surface. The electrode surface is integral with the body of the laminated wrapper.

BRIEF ESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a lamp discharge comprising a laminated envelope, the laminated envelope containing a gas discharge channel and a pair of external electrodes in communication with the gas discharge channel. Figure 1A is a cross section on the line X-X of Figure 1. Figure 2 is an equivalent circuit of plates in parallel of the discharge lamp shown in Figure 1. . «-j ** *** - .. * .... .teiiffif ^ illtáyf ^^ Figure 3 is a plan view of a discharge lamp comprising a laminated envelope, the laminated envelope containing a discharge channel gas and a pair of external electrodes of geometric configuration different from that of the external electrodes of Figure 1. Figure 3A is a cross-section on the line YY of Figure 3. Figure 4 is a perspective view of a lamp discharge comprising a laminated envelope, the laminated envelope including four separate gas discharge channels, in a horizontal parallel arrangement and external electrodes in communication with the opposite ends, and located thereon, of each gas discharge channel. Figure 5 is a perspective view of a discharge lamp comprising a laminated envelope, the laminated envelope including a continuous gas discharge channel in a serpentine configuration and external electrodes in communication with each, and located on each of the parallel sections of the gas discharge channel. Figure 6 is a cross-sectional view of a laminated wrapper suitable for the discharge lamp of the present invention, the laminated envelope including a gas discharge channel and external electrodes located on the upper outer surface, at opposite ends of the channel of gas discharge.

Figure 6A is a cross-sectional view of a laminated wrapper for the discharge lamp of the present invention, the laminated tffc casing including a gas discharge channel and external electrodes located on the outer top surface, at opposite ends of the gas discharge channel. Figure 6B is a cross-sectional view of a laminated wrapper suitable for discharge lamp of the present invention including the laminated wrapper a gas discharge channel and electrodes External ékts located on the upper and lower outer surfaces, in opposite ends of the gas discharge channel.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention is based on a discharge lamp 15 containing an envelope laminated with at least one gas discharge channel, in which the discharge is driven by external electrodes, the electrodes comprising an integral electrode surface with the laminated envelope and a conductive means disposed on the electrode surface. The laminated wrapper of the present invention is made according to the methods set forth in the patent application of E.U.A. No. 08 / 634,485 and the patent of E.U.A. No. 5,834,888 and the provisional patent application of E.U.A. in process Serial No. 60 / 076,968 which has the title "Channeled Glass Article and Method Thereof" and which has Stephen R. Alien as sole inventor; jointly assigned to the present assignee and incorporated herein by reference. In the patent application of E.U.A. Serial No. 08 / 634,485 and the US Pat. No. 5,834,888, the method of forming glass casings containing internally wrapped channels or laminated casings comprises the following steps: (a) supplying a first or channel forming strip of the molten glass to a surface of an assembly of mold having a mold cavity that possesses at least one forming groove of channel formed therewith and a peripheral surface, wherein the channel forming strip rests on the mold cavity and the peripheral surface of the mold assembly; (b) causing the molten glass channel forming strip to conform substantially to the contour of the mold cavity resulting in the formation of at least one channel of the glass strip melted; (c) supplying and depositing a second strip or molten glass sealant to the outer surface of the molten glass channel forming strip wherein the viscosity of the sealing strip is such that the sealing strip bridges but does not buckle by contacting the channel surface of the channel-forming strip, but is still sufficiently fused to forming an airtight seal wherever the sealing strip contacts the channel forming strip, thereby resulting in a glass article having at least one enclosed channel; (d) removing the glass article from the mold. The conformity of the strip of molten glass forming channel with the cavity is achieved of the mold by gravity forces, vacuum drive or a combination of both. The glass casing formed by the method t described above comprises a front surface and a back surface laminated and integrated with each other to form a unitary casing body 5 essentially free of any sealing materials and having at least one gas discharge channel . The laminated glass envelope exhibits a weight ratio to the area of < 1.0 g / cm2. In the provisional patent application of E.U.A. in process serial no. 60 / 076,968, the method of forming glass wraps or laminated wraps 10 comprises the following steps: (a) supplying a first or channel forming strip of the molten glass to a surface of a mold assembly which it has a mold cavity having at least one channel-forming groove formed therewith and a peripheral surface, wherein the channel-forming strip rests on the mold cavity and the peripheral surface of the mold assembly; (b) causing the molten glass channel forming strip to conform substantially to the contour of the mold cavity resulting in the formation of at least one channel of the molten glass strip; (c) supplying and depositing a second strip or fused glass seal to the outer surface of the molten glass channel forming strip 20 wherein the viscosity of the sealing strip is such that the sealing strip (i) bridges but is not camber by making full contact with the surface of at least one channel of the channel-forming strip and (i) forms an airtight seal wherever the sealing strip contacts the channel-forming strip ^ & ^ i ^. ^^. ,,, ^. ..., .A., ^^ - fc ^, .. ^^ «» ... ^ * ,, .., ^ _ "^. -J- TlriftiiíiiliiÉií ir i liiiiiífiriíiiíiii ¡^ ^^^^ - ^ • ^^^^^^ - ^ Ütá to form an article of glass with at least one channel enclosed; (d) causing the sealing strip to be stretched so that the sealing strip has a thin cross section and so that the seal between the sealing strip and the channel strip has a thin cross section; and (e) removing the glass article from the mold. The conformity of the strip of molten glass forming channel with the mold cavity is achieved by forces of gravity, vacuum drive, with a combination of both. The glass envelope formed by the method described above comprises an A front surface and a back surface laminated and integrated with each other to form a unit wrapping body essentially free of any sealing materials and having at least one gas discharge channel. The laminated glass envelope exhibits a weight ratio to the area of = 1.0 g / cm2. Figures 1 and 1A present a typical modality of the lamp of the present invention. The discharge lamp 20 comprises a laminated envelope 24 having a front surface 28 and a back surface 32 laminated and integrated with each other to form a unitary body essentially free of any sealing materials. Laminated wrap 24 exhibits preferably a ratio of the weight to the area of < 1.0 g / cm2. The laminated wrapper 24 includes the gas discharge channel 36. The tabulation door 40 is in communication with the external environment and the gas discharge channel 36. In the tabulation door 40, the discharge channel is evacuated. ^^^^^^^^^^^^^^^^^^^^ gas discharge 36 and refilled with an ionizable gas. After evacuation and refilling, the tabulation door 40 is sealed, whereby communication with the external environment is discontinued. • Any of the noble gases or mixtures of the same as the ionizable gas, including but not limited to, neon, xenon, krypton, argon, helium and mixtures thereof with mercury. In a preferred embodiment, the discharge lamp 20 is a neon lamp. A pressure of preferably 5-6 torr is used for the neon. < The laminated wrap 24 exposed above to the present is preferably made of a transparent material such as glass selected from the group consisting of sodium silicate lime, borosilicate, aluminosilicate, boroalumonosilicate and the like. The external electrodes 44 are in communication with each end, and located therein, of the gas discharge channel 36. It is achieved the communication between the external electrodes 44 and the gas discharge channel 36 via the tracks 48. It is to be understood, however, that the track 48 is present only by style design for reasons related to the procedure. Alternatively, the path 48 can be removed, whereby the gas discharge channel is contiguous with the external electrodes. It can also contemplate the application of conductive medium to the tracks, whereby the tracks are made because of the structure of the external electrodes. -...-- .. ^. ja. ^ ..-...-...; .. A. > - '-. .-... :: .. j .. .. .- - ^ 5¿_ & * ^ aíá¡fcaiiiflÍ¡ ^ aa & ^^^ A ballast or lina source of high voltage 100 is connected to the external electrodes by connecting wires 98 to drive the £ download. Ballasts and suitable connecting wires are well known in the art. Referring now to Figure 1A, the external electrode 44 comprises an electrode surface 52 and the connector means 60 disposed on said electrode surface 52. The electrode surface 52 forms an elongated receptacle. An important aspect of the present invention is that the electrode surface is integral with the structure of the envelope laminated. As such, the method for forming the envelope described hereinabove requires modification to allow simultaneous formation of at least one integral electrode surface with the laminated envelope. This can be achieved by modifying the mold cavity to include a groove forming the electrode surface, whereby a formation of a laminated envelope comprising a gas discharge channel and an electrode surface. As used herein, "electrode surface" refers to the section of the laminated wrap that is coated with a conductive means, forming an external electrode that can be coupled to an energy source. It is to be understood that the described method of forming the electrode surface is a preferred embodiment and that other forming methods can be used to achieve a similar wrapping structure, one such being a separate formation of a surface receptacle. of electrode and • - "-to .. - -i > 'j ^ ijis t ^? ^ iMsr'd ^ ..'--. . "..; -.-. . . ,;, w .... ,,. ». ? ^ ^ i ^^ SSÉ & ^^ lbiiAiím ^ B ^^ AÁsi á? It is added to the heat of discharge through a sealant such as glass frit. The discharge lamp shown in Figures 1 and 1A comprises a laminated envelope with two external electrodes. Alternatively, a laminated envelope comprises an electrode surface integral with the body of the laminated envelope and a conductive means disposed on the electrode surface is suitable for the present invention. A discharge lamp comprising an envelope ? k laminated with an external electrode and a gas discharge channel can to illuminate since, as is well known, the surrounding environment is a conductive medium and therefore effectively becomes a second external electrode. However, in order to achieve optimum operating conditions in a discharge lamp comprising a laminated envelope described above, a second external electrode must be provided; say the application of conductive tape or a separate structure of external electrode glass to the laminated envelope, whereby the second electrode • is in communication with the gas discharge channel. In the present invention, it has been discovered that the ability to effectively couple is a direct result of the process to form the envelope described hereinabove. More specifically, the forming process is particularly suitable for producing external electrode having a maximum electrode area and a minimum electrode thickness. The terms "electrode area" and "electrode thickness" it refers to the area of the conductive medium disposed on the electrode surface and the thickness of the glass of the electrode surface, respectively. The importance of the electrode area and the electrode thickness in the present invention becomes apparent after an investigation of Figure 2. This figure shows a simple RC circuit (resistance and capacitance), with parallel plates, of the discharge lamp 20, illustrated herein in Figure 1 and 1A. The RC circuit is connected to the stabilizer 68. The diagram shows in sene, two capacitors with parallel plates C-i and C2, each having a dielectric D, and a resistor RL. The two capacitors with parallel plates represent the external electrodes 44 and the ionizable gas in the gas discharge channel 36, which effectively form the conductors of the capacitors Ci and C2 the ionizable gas in a gas discharge 36 is a conductive medium and has an effective resistance represented by RL. Glass of the gas discharge channel 36 effectively acts as a dielectric D between the conductors and the capacitors Ci and C2. It is well known that the capacitance (C) of capacitors Ci and C2 filled, in a capacitor with parallel plates, is given by the formula: C =? (eoA / d) 20 where: K = dielectric constant < = o = permissiveness in space (C2 / N-m2) A = electrode area 1 d = electrode thickness. The capacitive reactance (CR) associated with the capacitors Ci and C2 is given by the formula: CR = 1 / (2p C) 5 where f = frequency of the stabilizer 68 C = capacitance. A preferred situation is achieved when CR is small. With low CR values, the excess voltage across the electrode is small, • 10 thus producing the maximum voltage requirement of the stabilizer. The luminous efficiency of the discharge lamp is optimized, by adjusting the excitation circuit to the load impedance. This is very easily achieved when CR is small compared to R, ie when CR is a fraction of RL. 15 Low CR values are obtained by increasing C or using high operating frequencies, ie 10 MHz or 1 GHz or more. The high • Operating frequencies are however expensive and give rise to other problems such as high electromagnetic interference. In order to meet customer requirements for low cost and energy efficiency, a goal of the present invention is to use low operating frequencies, preferably in the range of 100 KHz to 1000 KHz, and most preferably of about 250 KHz.

Therefore, in order to operate at low frequencies and to have low values of CR, C must be large. C for a filled capacitor must be f inversely proportional to the dielectric thickness and provide the surface area of the conductors. In the present invention, a C is obtained large decreasing electrode thickness and increasing the electrode area. As described hereinabove, small electrode area and thickness are achieved by the shell wrapping process. Briefly and more specifically, the stretching of the glass during the contouring process of a mold cavity reproved by gravity, the vacuum drive or a combination of both, gives a structure of maximum minimum thickness area at the electrode site. Therefore, in the present invention CR is a function of the envelope forming process. For effective accommodation at 250 kHz, the surface area of the electrode is in the range of 6.54-25.81 cm 2, and the thickness of the electrode is in a range of 0.5 mm to 1.5 mm, preferably approximately 0.75 mm. The present invention allows designs of discharge lamps that incorporate equivalent luminous efficiency, decreasing the length of the gas discharge channel and corrndingly increasing the current. Increasing the current and therefore the electronic deposition do not have an effect on the external electrodes, You > ^ ^ ^ r ^. ^. ^. ^. ^. ^. ^. ^ ^ 2 ^^? ^^. ^. ^. ^. ^. ^. ^. ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ J ^ t * > since its location is outside the envelope and not in direct contact with the ionizable gas ions. k is illustrated in the present invention by the non-limiting examples given in the following table. The lamps of neon discharge comprising laminated wraps with both internal and external electrodes. Example 1 is a discharge lamp comprising a laminated envelope having a gas discharge channel of 210 cm, the channel having a non-circular inner diameter of approximately 8 mm. Example 2 is a discharge lamp comprising a laminated wrapper having a gas discharge channel of 37cm, the channel having a non-circular inner diameter of approximately 5mm. Example 3 is a discharge lamp comprising a laminated envelope having a gas discharge channel of 140 cm, the channel having a non-circular diameter of approximately 5 mm. Example 4 is a lamp The discharge comprises a laminated envelope having a gas discharge channel of 55 cm, the channel having alternating narrow and narrow sections and an inner diameter in the narrow sections of 3 mm. Examples 1, 2 and 3 have an electrode thickness of 0.75 mm and example 4 has an electrode thickness of 0.50 mm. 20 The power source of the internal electrodes was a stabilizer driven at 30 mA DC. The point of operation was chosen as the point at which the light emission efficiency was the maximum, that is, at a lamp resistance of 50 kohm. An equal condition was maintained luminous efficiency for internal and external electrode configurations. The power source for the external electrodes was a variable frequency plasma generator. • iil ?? (or Ol Ol Coupling Coupling Coupling Coupling Coupling Coupling Electrode electrode coupling Electrode electrode Electrode electrode electrode internal internal external internal internal external internal internal external Frequency (kHz) 28 292 29 278 28 285 28 290 RL (kohms) 50 50 50 50 50 50 50 50 CR (kohms) - 9 - 50 - 8 6 Luminous performance 350 350 60 60 244 244 73 73 (lux) Energy 45.8 45.8 9.4 9 36.8 34.5 12 2 12.5 (watts) Emission efficiency of 7.64 7.95 6.38 6.67 6.63 7.07 5.98 5.84 light (lux / watt) (OR It has been observed that there is no fundamental difference in how Referring now to fi les 3 3A to arecen 88. The external electrodes 88 are external communication with the channel 84 gas discharge through the pathways 90. The external electrodes 88 include the electrode 92 and the conductive means 94 disposed on the surface of electrode 92, as illustrated in Figure 3A. The electrode surface 92 forms a plurality of contiguous round receptacles. The conductive medium 94 is applied as a coating or a film including, but not limited to, conductive coatings, conductive epoxy resins, conductive inks, frit with conductive filling and the like, or mixtures thereof. An example of a suitable conductive coating as the conductive medium is indium tin oxide. an oxide coating indium tin is formed, not limited to, sputtering, evaporation, chemical deposition and ion implantation. In a further embodiment, a discharge lamp comprises a laminated envelope, wherein the laminated envelope • comprises a plurality of separate gas discharge channels and external electrodes in communication with said channels, thereby driving a parallel discharge, lustra as in figure 4. the lamp 20 discharge 50 comprises the laminated shell 54, wherein said overwrap laminate comprises four gas discharge channels 56 spaced in parallel arrangement. The external electrodes 58 are in communication with the opposite ends, and located therein, of each ^^^^^^^^^^^^^^^^^!? ^^^^^ gas discharge channel 56. ll Iace connecting the stabilizer 62 with the connecting wires 60. Referring now to Figure 5, is illustrated in The same other embodiment of a discharge lamp 70. The discharge lamp 70 comprises the laminated envelope 72, wherein said laminated envelope comprises a continuous gas discharge channel 76 in a configuration in a serpentine configuration. The external electrodes 76 are in communication with each of the parallel sections, and located thereon of the gas discharge channel 76. The connection is made to the stabilizer 80 with the connecting wires 78. Referring now to Figures 6, 6A and 6B, illustrated in the same cross-sectional views are additional embodiments of laminated sheet wrappers suitable for the present invention. The laminated envelope 90 comprises a gas discharge channel 94 and external electrodes 98. In the embodiments illustrated in Figures 6 and 6A, the outer electrodes as a coating or film applied directly to the upper outer surface of the gas discharge channel 94 and are located at each end of the channel. In the embodiment illustrated in Figure 6B, external electrodes are applied as coating or film directly to the upper and lower outer surfaces of the gas discharge channel 94. While there have been exposed modalities now preferred embodiments of the invention will be apparent to those skilled in the art that do anflttat - »- -» & amp; 40H > s hßtMKk * auB l *? & * '«&' * -« w..a8fc «« -. various changes and modifications thereto, without deviating from the spirit and scope of the invention as set forth in the following claims. • •

Claims (24)

NOVELTY OF THE INVENTION CLAIMS •

1. A laminated glass casing for use as a discharge lamp, said laminated glass casing having a front surface and a back surface integrated together to form a unitary casing body essentially free of any sealing materials and exhibiting a Weight ratio to the area of < 1.0 g / cm2, 10 comprising said laminated glass shell: a gas discharge channel enclosed within said laminated glass shell; two external electrodes in communication with each end, and located thereon, of said gas discharge channel for driving an electric discharge in said gas discharge channel; characterized in that each of said 15 external electrodes includes an electrode surface integrally molded with said wrapping body and coated with a conductive means.

2. The laminated glass envelope according to claim 1, further characterized in that said external electrode has an electrode area and an electrode thickness that makes possible the 20 effective coupling at an operating frequency of 100 kHz to 1000 kHz, preferably at about 250 kHz.

3. - The laminated glass envelope according to claim 2, further characterized in that said electrode area is in the range of 6.54 cm2 to 25.81 cm2.

4. The laminated glass envelope according to claim 2, further characterized in that said electrode thickness is in the range of 0.5 mm to 1.5 mm, preferably 0.75 mm.

5. The laminated glass envelope according to claim 1, further characterized in that said electrode surface f is formed as an elongated receptacle.

6. The laminated glass envelope according to claim 1, further characterized in that said electrode surface is formed as a plurality of continuous round receptacles.

7. The laminated glass envelope according to claim 1, further characterized in that said laminated envelope of * < The glass is made of a glass selected from the group consisting of borosilicate, aluminosilicate, boroaluminosilicate and soda lime silicate.

8. The laminated glass envelope according to claim 1, further characterized in that said gas discharge channel is evacuated and filled with ionizable gas selected from the group that 20 consists of neon, xenon, krypton, argon, helium and mixtures thereof with mercury.

9. - The laminated glass envelope according to claim 8, further characterized in that said ionizable gas is neon to • a pressure of 5 torr to 6 torr. '& 10.- The laminated glass envelope in accordance with the 5 claim 1, further characterized in that said conductive medium is selected from the group consisting of conductive tape, conductive inks, conductive coatings, frit with conductive filling and conductive epoxy resins. 11.- The laminated glass envelope in accordance with the • 10 claim 10, further characterized in that said conductive coating is indium-tin oxide. 12. The laminated glass casing according to claim 11, further characterized in that said indium-tin oxide is applied to said electrode surface with a method selected from the group consisting of electronic deposition, evaporation, chemical deposition and implants. of ions. 13. The laminated glass casing according to claim 1, further characterized in that said laminated glass casing comprises a casing of gas discharge channels. 14. A laminated glass casing for use as a discharge lamp, said laminated glass casing having a front surface and a back surface integrated together to form a unitary casing body essentially free of any materials sealers and exhibiting a weight ratio to the area of < 1.0 g / cm2, said laminated glass envelope comprising: a discharge channel of f. gas enclosed within said laminated glass envelope, said gas discharge channel having a serpentine configuration; a plurality of 5 external electrodes in communication with parallel sections, and located thereon, of said serpentine gas discharge channel for driving an electric discharge in said parallel gas discharge channel; further characterized in that each of said external electrodes includes an integrally molded electrode surface with 10 said wrapping body and coated with a conductive means. 15. A discharge lamp comprising a laminated envelope, said laminated envelope comprising a front surface and a back surface integrated with each other to form a unitary envelope body free of any sealing materials, said 15 laminated casing a gas discharge channel formed in serpentine form and a plurality of external electrodes in communication with said gas discharge channel, thereby driving a parallel discharge. 16. A method for forming a discharge lamp driven by external electrodes, said method comprising the steps of: (a) 20 forming an electrode surface on a laminated envelope comprising a gas discharge channel, said electrode surface forming an integral part with said laminated envelope, said electrode surface being in communication with said gas discharge channel, The present invention comprises an anterior surface and a rear surface integrated with each other to form a wrapping body. • unit essentially free of any sealing materials; and (b) When applying a conductive medium on said electrode surface. 17. The method according to claim 16, further characterized in that said electrode surface is formed simultaneously with said laminated envelope. 18. The method according to claim 16, f further characterized in that said external electrode comprises an area of electrode and a thickness of electrode glass. 19. The method according to claim 18, further characterized in that said electrode area is in the range of 6.54 cm2 to 25.81 cm2. 20. The method according to claim 18, further characterized in that said thickness of electrode glass is 0.5 to 1.5 mm, preferably about 0.75 mm. 21. The method according to claim 16, further characterized in that said conductive medium is selected from the group consisting of conductive tape, conductive inks, conductive coatings, frit with conductive filler and conductive epoxy resins. 22. The method according to claim 21, further characterized in that said conductive coating is indium tin oxide. ^? ^^ t ^^^^, ... ^ AgAfa ^ a ^ »» ,, ^ s- «. ^ ** »^ *, .. ^^^^^^. ^^^^ 23. The dev method according to claim 22, further characterized in that said indium-tin oxide is applied by electronic deposition. • The method according to claim 16, further characterized in that said application of said step of the conductive medium of the group consisting of electronic deposition, evaporation, chemical deposition and ion implantation is selected. • - "- • - - * - - - - ^ Mfcafc - ^ - ^» - fc- ^ «: .- *. T ^ ^ ^ ^ ^^^^ iftjg ^ ll-fflfilÉr-