JP2005243515A - Flat surface fluorescent lamp and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a flat surface fluorescent lamp without using frit glass in sealing two sheets of glass plates. <P>SOLUTION: By heating and melting the end part of glass plates 1a, 1b by burners 3a, 3b, this end part itself is sealed directly. Thereby, frit glass is not used, thus a substance hazardous to the environment such as lead contained in the frit glass and an organic solvent or the like used at sealing of the frit glass is not required. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flat fluorescent lamp used in a backlight of a liquid crystal display device, general illumination, and the like, and a method for manufacturing the same.

  The backlight used in a liquid crystal display device of a notebook personal computer is mainly an edge light system in which several thin fluorescent lamps are arranged at the end of a light guide plate. However, this method has a problem that the number of fluorescent lamps that can be used is limited, and there is a loss of light due to a light guide plate or the like, so that it is difficult to increase the luminance.

  From this background, direct-type backlights with multiple fluorescent lamps arranged on the back side of the screen are used for LCD screens and LCD TVs for desktop personal computers that require higher brightness. It has become. As for the direct type, about 8 narrow tube type fluorescent lamps are arranged in parallel on the back side of the screen, and further a reflector is arranged on the back side, so that the light emission surface side of the fluorescent lamp is made uniform. For this reason, it has become common to use a planar light source by arranging a diffusion plate for the purpose.

The brightness of the fluorescent lamp itself is about 20000 to 40000 cd / m ^2. However, when a planar light source using a reflector or a diffuser is used, the overall brightness is about several thousand cd / m ² due to light loss caused by these. It will be reduced. Although the brightness can be increased by increasing the number of fluorescent lamps, the number of drive circuits for driving the fluorescent lamps increases and the power consumption increases.

  Under such circumstances, a flat fluorescent lamp in which the fluorescent lamp has a flat shape has been used. Since the flat fluorescent lamp has a wide discharge space inside the lamp, it is relatively easy to obtain high luminance.

  When manufacturing a flat fluorescent lamp, generally, two glass plates using soda glass or the like are arranged opposite to each other so that a discharge space is formed in a state in which a rare gas is hermetically sealed. The four ends are sealed. For this sealing, frit glass (low melting point glass) is used. That is, frit glass is disposed on the four sides of both glass plates, and the frit glass is heated and melted to seal both glass plates.

  When the frit glass is heated and melted, if the temperature of the glass plate reaches the glass transition temperature, thermal expansion occurs abruptly, causing cracks and the like. For this reason, it is desired that the frit glass has a low melting point, and in many cases, lead oxide is used.

When frit glass is used, it is generally frit using a binder resin (thickener) such as ether cellulose, methyl cellulose, nitrocellulose and an organic solvent such as butyl carbitol acetate, butyl carbitol, terpineol. Seal the glass and glass plate. For this reason, drying of the organic solvent and baking of the binder resin are performed in the sealing step, and the frit is softened and fluidized by air-sealing by processing at a higher temperature. In addition, about the backlight apparatus used as the planar light source, the thing of patent document 1 and patent document 2 is known.
JP-A-4-332455 JP-A-10-92381

  However, when performing hermetic sealing using frit glass, severe conditions are imposed on temperature control in the sealing process, and there is a problem that the processing time is very long. As shown in the profile representing the temperature control during heating / cooling in FIG. 29, about 4 from the sealing of the four edges of the two glass plates by sealing the rare gas to the end of the annealing process. It takes time. This time may take a whole day and night depending on the equipment and materials used.

In addition, lead that is harmful to the environment is used for the components of the frit glass, and the organic solvent is also harmful to the environment. Bismuth oxide (Bi ₂ O ₃ ) or the like has come to be used as an alternative to lead in order to cope with environmental problems that have been increasing in recent years. However, there is a problem that the melting point is higher than that of lead.

  The present invention has been made in view of the above, and an object of the present invention is to provide a flat fluorescent lamp that can be sealed without using frit glass when sealing two glass plates. is there.

  Another object of the present invention is to provide a method for producing a flat fluorescent lamp capable of sealing two glass plates without using frit glass.

  The flat fluorescent lamp according to the first aspect of the present invention is characterized in that two glass plates are arranged to face each other, and end portions of both glass plates are heated and melted and sealed in a state in which a rare gas is sealed.

  The flat fluorescent lamp manufacturing method according to the second aspect of the present invention includes a step of arranging two glass plates facing each other and a step of heating and melting the ends of both glass plates in a state in which a rare gas is sealed. It is characterized by having.

  In the first and second aspects of the present invention, the ends of the two glass plates are heated and melted in a state in which the rare gas is enclosed, and the ends themselves are directly sealed, so that the frit is obtained. The ends of the two glass plates are sealed without using glass.

  In the first flat fluorescent lamp, an internal electrode is provided in an internal space formed by two glass plates, and a flat external surface is provided on the outer surface of the glass plate on the side from which light emitted from the internal space is extracted. By providing the electrode, the positive column is attracted to the glass plate, and the phosphor layer formed on the inner surface of the glass plate emits light strongly, so that the luminance can be increased.

  Two glass plates can be sealed without using frit glass, and the manufacturing time can be greatly shortened. In addition, substances that are harmful to the environment, such as lead contained in the frit glass and an organic solvent used for sealing the frit glass, can be eliminated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, in the flat fluorescent lamp according to the present embodiment, the phosphor layer 2 is applied to at least one of the opposed surfaces of the two translucent glass plates 1a and 1b arranged opposite to each other. The Although the figure shows a state in which the phosphor layer 2 is applied to the surface of the glass plate 1b, the phosphor layer 2 may be applied to the surface of the glass plate 1a, or the glass plate 1a. , 1b may be applied to both.

  A discharge space is formed between the glass plates 1a and 1b, and a rare gas is hermetically sealed in the discharge space. For this reason, the glass plates 1a and 1b need to be hermetically sealed.

  In the present embodiment, as shown in FIG. 1, the end portions of the glass plates 1a and 1b are heated and melted by the burners 3a and 3b, and the end portions themselves are familiarized to be directly sealed. The glass plates 1a and 1b have a rectangular shape, and at the time of sealing the end portions of the glass plates 1a and 1b, at least one side is heated and melted for sealing. Of course, two sides and three sides may be heat-melted and sealed, or all four sides may be heat-melted and sealed.

  In addition, as shown in FIG. 2, after the end portions of the glass plates 1a and 1b are heated and melted by the burners 3a and 3b, the end portions are sandwiched between steel plates or the like, and a pressing force is applied so as to hermetically seal. You may make it wear. Thereby, the edge part of glass plate 1a, 1b can be sealed firmly.

  When manufacturing a flat fluorescent lamp, it is necessary to provide an electrode. The electrode may be provided at a position inside the both ends of the flat fluorescent lamp, that is, in the discharge space, or a pair of internal electrodes may be provided outside the flat fluorescent lamp, that is, outside the discharge space. May be. As an example of the external electrode in this case, a configuration may be adopted in which a lead wire is wound from end to end along the outer surface of the lamp. Alternatively, an internal electrode may be disposed within one end of the flat fluorescent lamp, and an external electrode may be disposed outside.

  In the flat fluorescent lamp having such a configuration, when a voltage is applied to each electrode, a rare gas reacts in the discharge space to generate ultraviolet rays, and the ultraviolet rays are excited by the phosphor layer 2 so that visible light is emitted. Occur.

  Therefore, according to the present embodiment, the ends of the glass plates 1a and 1b are heated and melted by the burners 3a and 3b, and the ends themselves are directly sealed, thereby eliminating the need for frit glass. When using, the time required for sealing and the time required for cooling will be many hours, but the manufacturing time can be greatly reduced.

  According to this embodiment, since frit glass is not used, environmentally harmful substances such as lead contained in the frit glass and an organic solvent used for sealing the frit glass can be eliminated.

  According to the present embodiment, after the ends of the glass plates 1a and 1b are heated and melted, the ends are sandwiched between steel plates or the like and sealed with a pressing force, so that the glass plates 1a and 1b are sealed. Can be firmly sealed.

  In the present embodiment, the burners 3a and 3b are used when melting and heating the ends of the glass plates 1a and 1b, but other heating means such as a heater may be used.

  The size of the liquid crystal display device to which the flat fluorescent lamp of the present embodiment is applied can be from a small size of about 5 inches to a large size of about 50 inches.

[Second Embodiment]
In the present embodiment, a flat fluorescent lamp configured to obtain high luminance will be described.

  As shown in the plan view of FIG. 3 and the cross-sectional view of FIG. 4, the flat fluorescent lamp has light-transmitting glass plates 1a and 1b arranged opposite to each other, as in the first embodiment, and its end 4 A flat discharge vessel is formed by heating and melting the sides and sealing them. Phosphor layers 2a and 2b are formed on the facing surfaces of the glass plates 1a and 1b, respectively.

  A rare gas is sealed inside the planar discharge vessel as a discharge medium. Specifically, xenon, krypton, argon, neon, helium, and mercury vapor are used alone or in a mixture of two or more kinds and sealed at a sealing pressure of several kPa to several hundred kPa.

  Inside one end of the planar discharge vessel, a metal internal electrode 4 having a length substantially the same as the length in the long side direction of the planar discharge vessel is disposed. The internal electrode 4 is connected to an introduction line 5 a connected to one terminal of the power source 7. The lead-in wire 5a is hermetically sealed at the end of the planar discharge vessel. As the metal used for the internal electrode 4, for example, nickel, stainless steel, molybdenum or the like is used. Moreover, you may make it form the internal electrode 4 by screen-printing paste-form silver on the inner surface of glass plate 1a, 1b.

  A planar external electrode 6 is disposed on the outer surface of the glass plate 1a on the side from which the light emitted inside the planar discharge vessel is extracted. In the present embodiment, the planar shape of the external electrode 6 is a rectangular shape. As a method for forming the external electrode, for example, paste-like silver or the like may be screen-printed on the outer surface of the glass plate 1a, or an aluminum thin film may be attached to the outer surface of the glass plate 1a using an adhesive material. Good. The external electrode 6 is connected to the other terminal of the power supply 7 through the lead-in wire 5b. Since the external electrode 6 is provided on the glass plate 1a on the side from which light is extracted, it is desirable that the external electrode 6 be configured so as not to shield light emitted from the phosphor layers 2a and 2b as much as possible. In the present embodiment, the external electrode 6 is formed using a light-transmitting conductive material such as indium tin oxide (ITO).

  In the flat fluorescent lamp having such a configuration, an AC voltage such as a sine wave, a rectangular wave, or a pulse wave is applied between the internal electrode 4 and the external electrode 6 by the power source 7, so that the internal space of the flat discharge vessel is Discharge occurs. The discharge medium reacts with this discharge to emit ultraviolet rays, and the ultraviolet rays are converted into visible light by the phosphor layers 2a and 2b. At this time, a positive column is formed between the internal electrode 4 and the external electrode 6 inside the planar discharge vessel. Since the positive column has the property of being attracted to the external electrode 6 side, in the present flat fluorescent lamp, the phosphor layer 2a formed on the glass plate 1a emits light more strongly than the phosphor layer 2b.

  FIG. 5 is a graph showing changes in luminance when the thickness of the phosphor layer 2a is changed. Here, the thickness of the phosphor layer 2b was constant at 0 μm, and the luminance was measured from the glass plate 1a side. The visible light emitted from the phosphor layer 2a includes light traveling toward the glass plate 1a and light traveling toward the glass plate 1b.

  As shown in the graph, basically, the thicker the phosphor layer 2a, the stronger the light emission intensity by the phosphor layer 2a. On the other hand, when the phosphor layer 2a is thick, it becomes difficult to form a positive column, which causes a decrease in luminance. However, in the present embodiment, the strong light emitted from the phosphor layer 2a can be extracted directly to the outside of the glass plate 1a, and the strong light directed from the phosphor layer 2a to the glass plate 1b can also be obtained from the phosphor layer 2b or Since the light is reflected on the surface of the glass plate 1b and easily passes through the phosphor layer 2a and the glass plate 1a, it can be taken out to the outside, and even when the phosphor layer 2a is thickened, a rapid decrease in luminance is prevented.

  As shown in the rear view of FIG. 6 and the cross-sectional view of FIG. 7, the flat fluorescent lamp of the comparative example has a configuration in which the external electrode 6 is disposed on the outer surface of the glass plate 1b that is not the light extraction side. The same components as those in FIGS. 3 and 4 are denoted by the same reference numerals, and a duplicate description is omitted here.

  As described above, since the positive column has a property of being attracted to the external electrode 6 side, in the flat fluorescent lamp of the comparative example, the phosphor layer 2b formed on the surface of the glass plate 1b is more phosphor layer 2a. It emits more intensely.

  FIG. 8 is a graph showing a change in luminance when the thickness of the phosphor layer 2b in the flat fluorescent lamp of the comparative example is changed. The thickness of the phosphor layer 2a was fixed at 10 μm, and the luminance was measured from the glass plate 1a side. When the thickness of the phosphor layer 2b is increased from the initial value of 10 μm, the luminance increases, but when the thickness of the phosphor layer 2b is about 70 μm, the increase in luminance is saturated and the film thickness is further increased. Then, the brightness decreases.

  The reason why the luminance decreases when the phosphor layer 2b is thickened in the flat fluorescent lamp of the comparative example is considered as follows. Since the positive column formed by the discharge between the internal electrode 4 and the external electrode 6 is formed along the inner surface of the glass plate 1b on which the external electrode 6 is installed, the phosphor layer formed on the glass plate 1b 2b emits light strongly. The positive column is easy to be formed when the phosphor layer 2b is thin, but it is difficult to form the phosphor column 2b when the phosphor layer 2b is thick. Furthermore, since a part of the light emitted from the phosphor layer 2b is shielded by the phosphor layer 2a, the luminance is lowered.

  Therefore, according to the present embodiment, by arranging the planar external electrode 6 on the outer surface of the glass plate 1a on the light extraction side, the positive column is drawn toward the glass plate 1a side, and the inner surface of the glass plate 1a. Since the phosphor layer 2a formed on the substrate emits light strongly, the luminance can be increased.

  According to the present embodiment, by increasing the thickness of the phosphor layer 2a formed on the inner surface of the glass plate 1a, the intensity of the light emitted from the phosphor layer 2a is increased, and the phosphor layer 2b or glass Since the light reflected on the surface of the plate 1b easily passes through the phosphor layer 2a and the glass plate 1a, the luminance can be maximized.

  According to the present embodiment, as in the first embodiment, the ends of the glass plates 1a and 1b are heated and melted, and the ends themselves are directly sealed, thereby eliminating the need for frit glass. The manufacturing time can be greatly reduced as compared with the case where frit glass is used. In addition, substances that are harmful to the environment, such as lead contained in the frit glass and an organic solvent used for sealing the frit glass, can be eliminated.

  In the present embodiment, the planar shape of the external electrode 6 is a rectangle, but is not limited thereto. For example, as shown in the plan views of FIGS. 9 to 19, the external electrode 6 can have an arbitrary shape. Further, when the area of the external electrode 6 is 30% or less with respect to the area of the phosphor layer 2a, the amount of light shielded by the external electrode 6 is reduced, so that the material of the external electrode 6 is made non-translucent. It can also be a conductive material.

  In the present embodiment, the phosphor layer 2a is formed on the surface of the glass plate 1a and the phosphor layer 2b is formed on the surface of the glass plate 1b. However, the present invention is not limited to this. For example, ultraviolet rays and visible light emitted from the discharge medium may be directly extracted without forming a phosphor layer at all. Or as shown in sectional drawing of FIG. 20, it is good also as forming the fluorescent substance layer 2a only in the surface of the glass plate 1a, and not forming the fluorescent substance layer 2b in the surface of the glass plate 1b. At this time, as shown in the cross-sectional view of FIG. 21, instead of forming the phosphor layer 2b on the inner surface of the glass plate 1b, the reflective film 8 may be formed, or as shown in the cross-sectional view of FIG. The reflective film 8 may be formed on the outer surface of the glass plate 1b.

  As the phosphor layers 2a and 2b, those used for general illumination and cold cathode fluorescent lamps are used. For example, a plurality of phosphors having different emission colors may be mixed and applied to the surface of the glass plate, or a plurality of phosphors having different emission colors may be individually applied in stripes or dots.

[Third Embodiment]
As shown in the plan view of FIG. 23 and the cross-sectional view of FIG. 24, the flat fluorescent lamp in the present embodiment has a configuration in which the internal electrode 4 is sealed to the end portions of the glass plates 1a and 1b. Also in this flat fluorescent lamp, the ends of the glass plates 1a and 1b are heated and melted and sealed. When the end portions of the glass plates 1a and 1b are heated and melted and sealed, the internal electrode 4 is sealed to the end portions so as to be sandwiched between the end portions of the glass plates 1a and 1b. Also in this flat fluorescent lamp, the external electrode 6 is formed on the outer surface of the glass plate 1a on the light extraction side. In FIGS. 23 and 24, the same components as those in FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description is omitted here.

  Therefore, according to the present embodiment, even when the internal electrode 4 is directly sealed to the end portions of the glass plates 1a and 1b, the end portions of the glass plates 1a and 1b are heated and melted and directly sealed. By doing so, the manufacturing time can be greatly reduced as compared with the case of using frit glass.

  According to this embodiment, since frit glass is not used, environmentally harmful substances such as lead contained in the frit glass and an organic solvent used for sealing the frit glass can be eliminated.

  According to the present embodiment, even when the internal electrode 4 is directly sealed to the ends of the glass plates 1a and 1b, the external electrode 6 is disposed on the outer surface of the glass plate 1a on the side from which light is extracted. The positive column is attracted to the glass plate 1a side, and the phosphor layer 2a formed on the inner surface of the glass plate 1a emits light strongly, so that the luminance can be increased.

[Fourth Embodiment]
As shown in the plan view of FIG. 25 and the cross-sectional view of FIG. 26, the flat fluorescent lamp in the present embodiment has a configuration in which a pair of internal electrodes 4a and 4b are arranged in the long side direction inside both ends of the flat discharge vessel. It is. A planar external electrode 6 is formed on the outer surface of the glass plate 1a on the light extraction side. The lead-in wire 5a welded to the internal electrode 4a and the external electrode 6 are connected via a power source 7a, and the lead-in wire 5b welded to the internal electrode 4b and the external electrode 6 are connected via a power source 7b.

  Also in this embodiment, a planar discharge container is comprised by heat-melting and sealing the edge part 4 sides of the glass plates 1a and 1b. In FIG. 26, as an example, the phosphor layer 2a is formed only on the inner surface of the glass plate 1a, and the phosphor layer 2b is not formed on the inner surface of the glass plate 1b.

  In this flat fluorescent lamp, a voltage is applied between the internal electrode 4a and the external electrode 6 by the power source 7a, and a discharge is started by applying a voltage between the internal electrode 4b and the external electrode 6 by the power source 7b. To do. At this time, a discharge region A is formed between the internal electrode 4a and the external electrode 6, and a discharge region B is formed between the internal electrode 4b and the external electrode 6 to obtain a light emitting surface.

  Therefore, according to the present embodiment, by using two internal electrodes 4 and two power sources 7, each of the internal electrodes 4a, 4b and the external electrode 6 shares a light emitting region. The driving voltage can be reduced compared to the case where only one is used.

  According to the present embodiment, the manufacturing time can be greatly shortened as compared with the case where frit glass is used by heating and melting and directly sealing the ends of the glass plates 1a and 1b. Further, since no frit glass is used, environmentally harmful substances such as lead contained in the frit glass and organic solvents used for sealing the frit glass can be eliminated.

  According to the present embodiment, by arranging the external electrode 6 on the outer surface of the glass plate 1a on the light extraction side, the positive column is drawn toward the glass plate 1a side and is formed on the inner surface of the glass plate 1a. Since the phosphor layer 2a emits light strongly, the luminance can be increased.

[Fifth Embodiment]
As shown in the plan view of FIG. 27 and the cross-sectional view of FIG. 28, the flat fluorescent lamp according to the present embodiment has four internal electrodes 4a to 4d arranged at predetermined intervals in the long side direction inside the flat discharge vessel. It is the arranged configuration. One terminal of the power source 7 is connected to the external electrode 6, and the other terminal is connected to the internal electrodes 4a to 4d via lead wires 5a to 5d, respectively.

  Also in this embodiment, a planar discharge container is comprised by heat-melting and sealing the edge part 4 sides of the glass plates 1a and 1b. FIG. 28 shows a state where the phosphor layer 2a is formed on the inner surface of the glass plate 1a and the phosphor layer 2b is formed on the inner surface of the glass plate 1b as an example.

  In this flat fluorescent lamp, when a voltage is applied between the internal electrodes 4a to 4d and the external electrode 6 by the power source 7, a discharge is generated, and a discharge region A, a discharge region B, a discharge region C, and a discharge region D are formed. Thus, a light emitting surface is obtained.

  Therefore, according to the present embodiment, since the number of the internal electrodes 4 is increased, the discharge region formed between the internal electrodes 4 and the external electrodes 6 is increased. A flat fluorescent lamp can be obtained.

  According to the present embodiment, the manufacturing time can be greatly shortened as compared with the case where frit glass is used by heating and melting and directly sealing the ends of the glass plates 1a and 1b. Further, since no frit glass is used, environmentally harmful substances such as lead contained in the frit glass and organic solvents used for sealing the frit glass can be eliminated.

  According to the present embodiment, by arranging the external electrode 6 on the outer surface of the glass plate 1a on the light extraction side, the positive column is drawn toward the glass plate 1a side and is formed on the inner surface of the glass plate 1a. Since the phosphor layer 2a emits light strongly, the luminance can be increased.

It is a figure which shows the manufacturing process of the flat fluorescent lamp in 1st Embodiment. It is a figure which shows another manufacturing process of the planar fluorescent lamp in 1st Embodiment. It is a top view which shows the structure of the planar fluorescent lamp in 2nd Embodiment. It is sectional drawing which shows the structure of the planar fluorescent lamp in 2nd Embodiment. It is a graph which shows the relationship between the thickness of the fluorescent substance layer of the planar fluorescent lamp in 2nd Embodiment, and a brightness | luminance. It is a rear view which shows the structure of the flat type fluorescent lamp of a comparative example. It is sectional drawing which shows the structure of the flat fluorescent lamp of a comparative example. It is a graph which shows the relationship between the thickness of the fluorescent substance layer of the flat fluorescent lamp of a comparative example, and a brightness | luminance. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is a top view which shows another shape of an external electrode. It is sectional drawing which shows the structure which did not provide the fluorescent substance layer in the inner surface of one glass plate. It is sectional drawing which shows the structure which replaced with the fluorescent substance layer and has arrange | positioned the reflecting film on the inner surface of the glass plate. It is sectional drawing which replaces with a fluorescent substance layer and shows the structure which has arrange | positioned the reflecting film on the outer surface of a glass plate. It is a top view which shows the structure of the planar fluorescent lamp in 3rd Embodiment. It is sectional drawing which shows the structure of the planar fluorescent lamp in 3rd Embodiment. It is a top view which shows the structure of the planar fluorescent lamp in 4th Embodiment. It is sectional drawing which shows the structure of the planar fluorescent lamp in 4th Embodiment. It is a top view which shows the structure of the planar fluorescent lamp in 5th Embodiment. It is sectional drawing which shows the structure of the planar fluorescent lamp in 5th Embodiment. It is a profile showing the temperature control at the time of heating and cooling at the time of sealing two glass plates using frit glass.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b ... Glass plate 2, 2a, 2b ... Phosphor layer 3a, 3b ... Burner 4, 4a-4d ... Internal electrode 5, 5a-5d ... Lead-in wire 6 ... External electrode 7a, 7b ... Power supply 8 ... Reflection film

Claims (5)

  A flat fluorescent lamp characterized in that two glass plates are arranged facing each other, and end portions of both glass plates are heated and melted and sealed in a state in which a rare gas is sealed.   2. The flat fluorescent lamp according to claim 1, wherein the ends of the two glass plates are heated and melted and sealed by applying a pressing force so as to sandwich the ends. An internal electrode provided in an internal space formed by two glass plates;
A planar external electrode provided on the outer surface of the glass plate on the side from which light emitted from the internal space is extracted;
A phosphor layer formed on the inner surface of the glass plate;
The flat fluorescent lamp according to claim 1 or 2, characterized by comprising: A step of opposingly arranging two glass plates;
A process in which the ends of both glass plates are heated and melted and sealed with a rare gas sealed;
A method for producing a flat fluorescent lamp, comprising: 5. The flat fluorescent lamp according to claim 4, wherein in the sealing step, the ends of the two glass plates are heated and melted and then sealed by applying a pressing force so as to sandwich the ends. Production method.

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