JPH09102297A - Plane light emission type of fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long life of plane light emission type of fluorescent lamp by suppressing the nonconformity such as the drop of brightness by the occurrence of sputtering at an electrode, unevenness of brightness by concentrated discharge, etc. SOLUTION: A phosphor 3 is applied on the inner face of a flat discharge container, and a pair of plate-shaped electrodes 20 and 30 are counterposed on the side face of the interior of this discharge container. The occurrence of the sputter is lessened, by providing a through hole or a bottomed hole at the surface of one electrode out of these electrodes, and widening the surface of the electrode so as to put it in hollow cathode shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat emission type fluorescent lamp used for a backlight of a liquid crystal display or the like.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the drawings. For example, in an example of a conventional flat-emission fluorescent lamp used as a backlight of a liquid crystal display,
As shown in FIG. 1, there is a pair of electrodes 4a and 4b and a flat box body 1 that houses the electrodes 4a and 4b to form a sealed discharge path. They are arranged in a hermetically sealed manner, and the phosphor 3 is applied to the inner surface of the bottom plate 6 of the box 1 and the inner surface of the glass upper plate 2. The phosphor 3 is applied thicker on the inner surface of the bottom plate 6 than on the inner surface of the glass upper plate 2. The symbol 5 indicates the remaining portion of the exhaust pipe in the exhaust step of manufacturing the fluorescent lamp.

Noble gas and mercury vapor are contained in the enclosed space.
Alternatively, only a rare gas is enclosed and the pair of electrodes 4
The ultraviolet rays generated by exciting mercury vapor and the ultraviolet rays generated by exciting a rare gas by causing a high-frequency discharge to occur on the entire electrode surface between a and 4b are the inner surface of the bottom plate 6 of the box 1 and the glass upper plate. It is converted into visible light by the phosphor 3 applied to the inner surface of 2 and is emitted as flat light from the glass upper plate 2 to the outside.

[0004]

A pair of electrodes 4a, 4b.
Uses an electrode that operates in the cold cathode mode. The electrode operating in the cold cathode mode has a problem during lamp lighting. For example, scattering of oxides formed on the electrode surface or impurities adhering to the electrode surface,
Alternatively, the emission of an impure gas from the inside of the electrode due to the high cathode drop voltage, or the sputtering of the electrode itself causes a problem such as a decrease in brightness and uneven brightness due to discharge concentration. For the purpose of preventing such a problem, in most cases, the electrode is made of a refractory metal, and further, the discharge area is increased to reduce the current density, and the degassing treatment of the pretreatment is sufficient. Consideration is given.

As described above, in the flat-emission fluorescent lamp, the electrode area is widened to reduce the current density in order to secure a long life, and the pretreatment is sufficiently performed to reduce the spatter from the electrode. However, the recent flat-emission fluorescent lamps are required to be further miniaturized. The smaller the size, the smaller the electrode area of the fluorescent lamp. That is, since the current density becomes large, there is a problem that spatter occurs at an early stage, the brightness is lowered, and the uneven brightness occurs due to discharge concentration. The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a flat-emission fluorescent lamp having a long service life by minimizing spatter from electrodes.

[0006]

[Means for Solving the Problems]

<Means 1> A flat surface in which a phosphor is applied to the inner surface of a flat container, and a pair of plate-shaped electrodes are arranged inside the container so as to face each other, a discharge space is formed between the two electrodes, and high-frequency lighting is performed. In the light emitting fluorescent lamp, a flat light emitting fluorescent lamp is characterized in that a through hole is provided on the surface of one of the above electrodes, thereby suppressing the occurrence of spatter during discharge. <Means 2> A flat surface in which a phosphor is applied to the inner surface of a flat container, and a pair of plate-shaped electrodes are disposed inside the container so as to face each other, a discharge space is formed between the two electrodes, and high-frequency lighting is performed. In a light emitting fluorescent lamp, a flat light emitting fluorescent lamp is characterized in that a bottomed hole is provided on the surface of one electrode of the above electrodes facing the other electrode. Suppresses the generation of spatter.

[0007]

By providing a through hole or a bottomed hole in the electrode, the surface area of the electrode is increased, the current density is reduced, and the generation of spatter is reduced. Further, since the electrode has a hollow cathode shape, the cathode drop voltage is suppressed to a low level and the generation of spatter is reduced.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The flat-emission fluorescent lamp of the present invention will be described in detail below. 3 and 4 have outer dimensions of 18 mm × 15 mm × 4 mm and power consumption of 0.4 W.
3A and 3B are a perspective view and a sectional view of the flat-emission fluorescent lamp of FIG.
In FIG. 3, the glass upper plate 2 which is the light emitting surface is made of soft glass such as soda lime glass, and the bottom plate 6 and the rectangular frame spacer plate 7 are made of ceramics such as forsterite. As shown in FIG. 4, the bottom plate 6 and the frame spacer plate 7 have a flat box shape integrated in advance, and the translucent glass upper plate 2 is placed on the frame spacer plate 7.
Are sealed by the low melting point glass 8. That is, a flat closed light emitting space 9 is defined by the glass upper plate 2, the bottom plate 6 and the frame spacer plate 7, and the phosphor 3 is applied to the glass upper plate 2 and the bottom plate 6.

In the flat-emission fluorescent lamp of the present invention, the phosphor 3 of the bottom plate 6 is applied thicker than the phosphor 3 of the glass upper plate 2 in order to utilize the light emission in one direction. In the light emitting space 9, a predetermined amount of a mixed gas of argon and xenon,
In some cases, mercury is additionally included. The first electrode 20 and the second electrode 30 are arranged opposite to each other in the vicinity of both ends in the light emitting space 9, and high frequency discharge is performed between the first electrode 20 and the second electrode 30. Further, the bottom plate 6 and the frame spacer plate 7 may be made of soft glass made of the same material as the glass upper plate 2, and a reflection plate may be attached to the outer surfaces of the bottom plate 6 and the frame spacer plate 7.

FIG. 5 is a perspective view of the first electrode 20. The flat electrode portion 20 'for discharging is Ta, Mo, Ni,
High melting point metal such as Fe-Ni-Cr alloy is used, width 2.0mm, length 11mm, thickness 0.2m.
It is a plate shape of m. Further, the low melting point glass sealing portion 21 and the lead portion 22 which are sealed with the low melting point glass have a width of 1.
Electrode flat surface 2 having a strip shape of 0 mm and a thickness of 0.2 mm
0'and the lead portion 22 are integrally formed. The electrode plane portion 20 ′ and the lead portion 22 may be joined by spot welding or the like without integrally forming the electrode plane portion 20 ′ and the lead portion 22.

Further, the electrode flat surface portion 20 'of the first electrode 20.
Nine conical hole portions 23 formed by molding are provided on the surface. Regarding the number, position and shape of the holes, holes having an appropriate shape may be provided in an appropriate number and at an appropriate position so that the surface area becomes large according to the requirements such as lamp input or changes in lamp dimensions. Although the hole 23 has a conical shape by molding, as shown in FIGS. 6 and 7, a cylinder, an elongated hole, a combination thereof, or the like, for example, the thickness of the electrode flat surface portion 20 ′ is the thickness of the lead portion 22. Properly according to the specifications of the lamp, such as making it thicker and making holes.

The present invention in which a through hole or a bottomed hole is provided on the electrode surface of one of a pair of electrodes inside a flat-emission fluorescent lamp is the top plate and the bottom plate described so far in the above embodiments. In addition to the flat emission type fluorescent lamp having a structure in which separate members such as a frame spacer plate are combined, a flat emission type fluorescent lamp in which a flat shape is integrally formed by crushing a cylindrical lamp container is used. It is applied to the entire circumference of the inner surface of the lamp container, the phosphor on one flat surface of the inner surface is thickly applied, or a reflective tape is arranged on the surface corresponding to the outer surface of the one flat surface on the outside of the lamp, and the other flat surface. It should be noted that the present invention can also be applied to a flat-emission fluorescent lamp that uses light emitted in one direction from the.

Next, an experimental example of the present invention will be described.
Table 1 shows the results of examining the relationship between the lamp lighting time of the flat-emission fluorescent lamp according to the present invention and the start time of sputtering at the electrodes. 9 through holes in the first electrode on the cathode operating side
A comparison is made of a flat-emission fluorescent lamp in which mercury is enclosed in a total of three types of electrodes, that is, electrodes provided at 18 or 18 places and a conventional flat electrode without a hole which is an electrode on the cathode operating side. The spatter is visually confirmed, and if a small amount of spatter occurs in the vicinity of the electrode, the spatter is minutely generated. As the amount of spatter increases, the black spot occurs at a blackening degree of 1, and the blackening of the light emitting surface progresses. As a result, arrangement evaluation was performed up to a blackening degree of 5. It can be seen from Table 1 that in the flat-emission fluorescent lamp having the electrode of the present invention, the start time of spatter generation at the electrode is later than in the flat-emission fluorescent lamp having the conventional electrode.

[0014]

[Table 1] Elapsed lighting time and spatter generation status Table 2 shows the electrode with 9 bottomed holes on the cathode side.
Or, it is the result of performing the flat emission type fluorescent lamp having a total of three types of electrodes, that is, an electrode provided with nine through holes and a conventional flat plate electrode without a hole which is an electrode on the cathode operating side,
It is the relationship between the lighting time and the luminance decay rate. The brightness retention rate was calculated by measuring the central brightness on the phosphor surface coated on the glass upper plate with a brightness meter.

[0015]

[Table 2] Lighting time and luminance decay rate

[0016]

As described above in detail, in the flat-emission fluorescent lamp of the present invention, the surface area of the electrode is increased and the surface area of the electrode is increased by providing the electrode with the through hole or the bottomed hole. Since the hole has a hollow cathode shape capable of suppressing the cathode drop voltage to a low level, it is possible to provide a flat emission type fluorescent lamp with little spatter and a long life.

[Brief description of the drawings]

FIG. 1 shows a perspective view of a conventional flat-emission fluorescent lamp.

FIG. 2 shows a perspective view of electrodes of a conventional flat-emission fluorescent lamp.

FIG. 3 shows a perspective view of a flat-emission fluorescent lamp of the present invention.

FIG. 4 shows a cross-sectional view of a flat-emission fluorescent lamp of the present invention.

FIG. 5 shows a perspective view of electrodes of a flat-emission fluorescent lamp of the present invention.

FIG. 6 is a sectional view schematically showing a modification of the electrodes of the flat-emission fluorescent lamp of the present invention.

FIG. 7 is a front view schematically showing a modification of the electrodes of the flat-emission fluorescent lamp of the present invention.

[Explanation of symbols]

 1 Box 2 Glass Upper Plate 3 Phosphor 4a Electrode Part 4b Electrode 5 Exhaust Pipe Remaining 6 Bottom Plate 7 Frame Spacer Plate 8 Low Melting Glass 9 Light Emitting Space 20 First Electrode 20 'Electrode Flat 21 21 Low Melting Glass Sealing Part 22 lead part 23 hole part 30 second electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Suenaga 1194 Sado, Bessho Town, Himeji City, Hyogo Prefecture Ushio Electric Co., Ltd.

Claims (2)

[Claims] 1. A phosphor is applied to the inner surface of a flat container,
And a pair of plate-shaped electrodes are arranged to face each other inside the container,
A flat-emission fluorescent lamp in which a discharge space is formed between the two electrodes and which is lit at a high frequency, wherein a through hole is provided on the surface of one of the electrodes. 2. A phosphor is applied to the inner surface of a flat container,
And a pair of plate-shaped electrodes are arranged to face each other inside the container,
In a flat-emission fluorescent lamp in which a discharge space is formed between the two electrodes and which is lit at high frequency, a bottomed hole is provided on the surface of one of the electrodes facing the other electrode. The feature is a flat emission fluorescent lamp.