JPH04277461A - Electric discharge lamp with cold cathode - Google Patents

Abstract

PURPOSE:To provide an electric discharge lamp of cold cathode type equipped with an enhanced light emission efficiency. CONSTITUTION:A plate-shaped electrode 10 is furnishes, a part whereof is located between a glass bulb 1 and a stem 4 at the end thereof. The side face of this plate-shaped electrode 10 shall face the aperture part 3 so that the apparent area of the plate form portion as viewed from the aperture part 3 minimizes. Thereby the Hg sputtered to the aperture part 3 is prevented from attaching, and also the effective length of discharge path is elongated. Thus drop of the light emission efficiency is precluded.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold cathode discharge lamp with high luminous efficiency.

0003

[Prior Art] This type of conventional aperture-type cold cathode discharge lamp emits mercury from a plate-shaped electrode, and the plate-shaped electrode is attached to the discharge circuit side from the stem provided at the end of the bulb, and the plate-shaped electrode is attached to the side of the discharge circuit from the stem provided at the end of the bulb. Discharging is being carried out.

0004

Therefore, there is a problem in that no discharge occurs in the stem portion at the end of the bulb, resulting in a dark area at the end of the bulb, resulting in a shortening of the effective light emission length.

Furthermore, since lighting is performed by evaporating mercury from the plate-shaped electrode, mercury and other substances adhere to the end of the bulb near the plate-shaped electrode, which can reduce the luminous efficiency, especially if the aperture part becomes dirty. It has a significant problem.

The present invention was made in view of the above problems, and an object of the present invention is to provide a cold cathode discharge lamp with increased luminous efficiency.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] The cold cathode discharge lamp according to claim 1 is an aperture type cold cathode discharge lamp having a plate-like electrode for emitting mercury and an aperture portion, wherein the plate-like electrode is connected to the aperture portion. The plate is installed so that the apparent area of the plate-like part is the minimum area when viewed from the outside.

In the cold cathode discharge lamp according to the second aspect of the invention, a stem is sealed to the end of the bulb, a plate-shaped electrode for discharging mercury is attached to the tip of the stem, and the plate-shaped electrode side of the stem and the bulb are attached. In an aperture-type cold cathode discharge lamp having an aperture portion and a gap therebetween, the plate-shaped electrode is attached so that the apparent area of the plate-shaped portion is a minimum area when viewed from the aperture portion, and
At least a part of the plate electrode is disposed in a gap between the plate electrode side of the stem and the bulb.

0010

[Function] In the cold cathode discharge lamp according to claim 1, the plate electrode is arranged so that the area of the plate electrode is minimized when viewed from the aperture part, and when mercury evaporates from the plate electrode, the aperture part This prevents mercury, etc. from scattering and reduces luminous efficiency.

In addition to the cold cathode discharge lamp according to claim 1, the cold cathode discharge lamp according to claim 2 further includes a part of the plate electrode inserted into the gap between the plate electrode side of the stem and the bulb. , the distance between the plate-like electrodes is lengthened without increasing the length of the bulb, thereby shortening the portion where the dark portion occurs and increasing the effective light emission length to increase the light emission efficiency.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cold cathode discharge lamp of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, 1 is a glass bulb, and this glass bulb 1 has a phosphor 2 coated on its inner wall.
It is baked, and an aperture portion 3 is formed along the longitudinal direction on one surface, and this aperture portion 3 irradiates light. Further, a stem 4 is sealed to both ends of the glass bulb 1, and an exhaust pipe 5 for exhaust is attached to the stem 4. Furthermore, a gap 6 is formed between the stem 4 and the glass bulb 1.

Two wells 9 consisting of an inner well 7 and an outer well 8 are sealed to each stem 2 at both ends. The inner well 7 has a mercury alloy and a getter at its tip, and a rectangular plate-like metal pellet with the mercury alloy on the inner surface and the tip bent and widened at 20° to 60°. A plate-shaped electrode 10 made of . The plate electrode 10 is disposed so that the side face faces the aperture part 3, that is, the apparent area of the plate part seen from the aperture part 3 is minimized, and it is expanded. The rear end of the plate-shaped electrode 10 is interposed between the stem 4 and the glass bulb 1.

Further, the outer wells 8 is led out from the sealed exhaust pipe 5 and is connected to a power source or the like.

The brightness distribution of this cold cathode discharge lamp has a directivity in which the brightness is highest in the direction of the aperture portion 3, as shown by the solid lines in FIGS. 4 and 5.

Further, as shown in FIG. 6, a reflective film 11 made of, for example, silicon oxide (SiO2), titanium oxide (TiO2), or aluminum oxide (AlO2) is used.
may be provided on the inner surface of the glass bulb 11, and the one surface without the reflective film 11 may be used as the aperture portion 3. Furthermore, Figure 7
As shown in the figure, a flat plate-shaped electrode 10 may be used.

Then, the plate-like electrode 10 is connected to the aperture section 3.
The side surface faces the aperture part 3 so that the apparent plate-like part has the smallest area, and it is bent with the mercury alloy on the inner surface, so even if mercury scatters, it is difficult to stick to the aperture part 3. , as shown by the solid line in Figure 5,
It is possible to prevent a decrease in luminous efficiency, especially at the ends, compared to the conventional case shown by the broken line.

Furthermore, by inserting the plate electrode 10 between the stem 4 and the glass bulb 1 and bringing it as close to the end of the glass bulb 1 as possible, the plate electrode 10 can be extended without making the glass bulb 1 longer. By increasing the length of the discharge path without contacting the glass bulb 1 and stem 2, the effective length of the discharge path is increased.

[0020]

According to the cold cathode discharge lamp according to claim 1, the plate-shaped electrode is arranged so as to minimize the area of the plate-shaped electrode in the apparent plate-shaped portion seen from the aperture portion. Even if mercury is emitted from the plate-shaped electrode, it is difficult to adhere to the aperture portion, so it is possible to prevent a decrease in light output efficiency.

According to the cold cathode discharge lamp according to claim 2, in addition to the cold cathode discharge lamp according to claim 1, a part of the plate electrode is disposed in the gap between the bulb and the stem.
The plate electrode can be placed close to the end of the glass bulb, and the effective discharge path length can be increased without increasing the length of the bulb itself, making it possible to increase the efficiency of light output. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing an embodiment of a cold cathode discharge lamp of the present invention.

FIG. 2 is a partial sectional view of the same as above.

FIG. 3 is a partial cross-sectional view of the same as above.

FIG. 4 is a brightness distribution diagram seen from the side of the same as above.

FIG. 5 is a brightness distribution diagram in the direction of the aperture portion of the same as above.

FIG. 6 is a longitudinal sectional view showing another embodiment.

FIG. 7 is a cross-sectional view showing another embodiment.

[Explanation of symbols]

1 Glass bulb 3 Aperture part 4 Stem 6 Gap 10 Plate electrode

Claims (2)

[Claims] 1. An aperture-type cold cathode discharge lamp having a plate-like electrode that emits mercury and an aperture portion, wherein the plate-like electrode has a minimum apparent area of the plate-like portion when viewed from the aperture portion. A cold cathode discharge lamp characterized in that it is installed so that. 2. A stem is sealed to the end of the bulb, a plate-shaped electrode for releasing mercury is attached to the tip of the stem, and a gap is provided between the plate-shaped electrode side of the stem and the bulb, and an aperture portion is provided. In the aperture-type cold cathode discharge lamp, the plate-shaped electrode is attached so that the apparent area of the plate-shaped part when viewed from the aperture part is the minimum area, and the plate-shaped electrode side of the stem and the plate-shaped electrode A cold cathode discharge lamp characterized in that at least a part of the plate-shaped electrode is disposed in a gap between the lamp and the bulb.