JPH04109546A - Cold cathode fluorescent lamp - Google Patents

Abstract

PURPOSE:To improve brightness with discharge current increased by providing a platelike electrode part in two stages, and enlarging the surface area of an electrode. CONSTITUTION:Every two wells 4 are sealed in each stem 2 on both ends, and the well 4 is formed with inner and outer wells 5 and 6. Moreover a getter, having the main body of an intermetallic compound, is provided or the base end side surface respectively, two metal pellets 7 and 8, their tips are folded in a V-shaped and acute angle state, as platelike electrode parts are welded, and an electrode 9 is formed in the tip of the inner well 5. These metal pellets 7 and 8 are fitted nearly parallelly and so as not to be mutually contacted. Moreover the pellets 7 and 8 are made in two stages and the surface area of the platelike electrode 9 is widened. This can improve brightness with discharge current increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a cold cathode fluorescent lamp used for liquid crystal display of office automation equipment, backlight of automobile meter, etc.

(Prior Art) In recent years, cold cathode fluorescent lamps of this type are required to improve brightness without increasing the size of the cold cathode fluorescent lamps in order to downsize equipment. One way to improve this brightness is to increase the discharge current.

However, since cold cathode discharge lamps generally utilize a glow discharge region, increasing the current increases the deterioration of the electrodes due to ion bombardment and shortens the life of the electrodes. As a countermeasure to this problem, a method of increasing the electrode surface area has been adopted.

As a device for increasing the electrode surface area, for example, the device shown in FIG. 4 is known. This is a glass bulb 1 - phosphor is coated and baked on the inner wall, and on both ends,
Stem 2 is sealed.

Further, an exhaust pipe 3 is attached to the stem 2. Two wells 4 are sealed to each stem 2, and the wells 4 are formed of an inner well 5 and an outer well 6. In addition, the tip of the inner well 5 has a mercury alloy and a getter,
Two plate-shaped electrodes 9 made of metal pellets 7 and 8, each having an acute angle at the tip, are overlapped and welded. In this way, deterioration of the electrode 9 is reduced.

However, in the cold cathode fluorescent lamp shown in FIG. 4, the surface area of the electrode 9 cannot be made sufficiently large unless the diameter of the bulb l is increased. Although not publicly known, it has been proposed that two letter-shaped metal pellets 7 and 8 with a fan-shaped cross section are welded to the tip of the inner well 5.

(Problems to be Solved by the Invention) However, in the case of the configuration shown in FIG. 5, although the blackening phenomenon of the electrode 9 is reduced, there is a problem that there are many variations.

Additionally, experiments have revealed that this variation is largely due to the spacing between adjacent metal pellets.

The present invention was made in view of the above problems, and an object of the present invention is to provide a cold cathode fluorescent lamp that can improve brightness and prevent deterioration of electrodes.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a cold cathode lamp in which an inner wall of a bulb is coated with a phosphor and electrodes are sealed at both ends of the bulb. These plate-shaped electrode parts are connected to the inner well with gaps between adjacent plate-shaped electrode parts.

(Function) The present invention provides a plurality of plate-shaped electrode parts, increases the surface area of the electrodes, increases discharge current, and improves brightness without increasing the diameter of the bulb.

Furthermore, a gap is provided between adjacent plate-shaped electrode parts to eliminate overlap between the electrodes, thereby reducing occurrence of blackening and preventing deterioration of the electrodes.

(Example) Hereinafter, an example of the cold cathode fluorescent lamp of the present invention will be described with reference to the drawings.

Note that parts corresponding to those in the conventional example will be described with the same reference numerals.

As shown in Figures 1 and 2, the diameter is 9.5111m.
The inner wall of the straight cylindrical glass bulb 1 is coated and baked with phosphor, a stem 2 is sealed at both ends, and an exhaust pipe 3 for exhaust is attached to the stem 2. ing.

Two wells 4 are sealed to each stem 2 at both ends, and each well 4 is formed of an inner well 5 and an outer well 6. Furthermore, the tip of the inner well 5 has a mercury alloy mainly composed of an intermetallic compound of titanium and mercury on the proximal side, and a getter mainly composed of an intermetallic compound consisting of zirconium and aluminum on the distal side. Metal pellet as a plate electrode part bent at an acute angle in a dogleg shape 7.8
are welded together to form an electrode 9. These metal pellets 7.8 are mounted substantially parallel and so as not to touch each other.

Further, the outer wells 6 is led out from the sealed exhaust pipe 3 and is connected to a power source or the like.

In this way, the metal pellets 7.8 are arranged in two stages to increase the surface area of the plate electrode 9 without increasing the diameter of the glass bulb 1. By increasing the surface area of this electrode 9, the discharge current is increased and brightness is improved.

In addition, when we experimented with the state of lighting blacking at a lamp current of 10 mA, as shown in FIG. 4, the example shown in FIG. The phenomenon of the number of blackening points in A was reduced, and it was found that the less overlap of the metal pallets, the less the blackening phenomenon. This is thought to be due to the fact that the adjacent metal pellets 7.8 do not overlap.

[Effects of the Invention] According to the present invention, by arranging a plurality of plate-shaped electrodes with gaps and attaching them to the inner well, the surface area of the electrodes becomes larger, so it is possible to increase the discharge current. can. In addition, by disposing adjacent plate-shaped electrode portions with a gap between them, it is possible to suppress the blackening phenomenon of the electrodes, so that deterioration of the electrodes can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a cold cathode fluorescent lamp according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the same as above, FIG. 3 is a graph showing the relationship between the number of blackening points and lighting time, FIG. 4 is a partially cut-away side view of a conventional cold cathode fluorescent lamp, and FIG. 5 is a partially cut-away side view of another conventional cold cathode fluorescent lamp. 1...Glass bulb, 5...Inner wells, 7,8
... Metal pellet as a plate-shaped electrode part, 9... Electrode. 7 Fox Lady Four Misaki Vermilion 2 Figure Lighting Eye rrI (Wind Threshold) Cold 4 Balls

Claims (1)

[Claims] (1) In a cold cathode lamp in which the inner wall of the bulb is coated with phosphor and electrodes are sealed at both ends of the bulb, the electrode has a plurality of plate-shaped electrode parts, and these plate-shaped electrode parts are A cold cathode fluorescent lamp characterized in that it is connected to an inner well with a gap between adjacent plate electrode parts.