JPS6129097B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Field of Application of the Invention The present invention relates to a discharge lamp with a discharge vessel consisting of an inner and outer double glass bulb, in which the tip of the inner glass tube is narrowed and the outer glass bulb and the inner glass tube are combined. This invention relates to a small low-pressure discharge lamp in which a plurality of stable discharge paths are formed in a surrounding discharge space. A single-cap compact fluorescent discharge lamp is a typical application example of the present invention.

(2) Prior Art Conventional fluorescent discharge lamps for illumination generally have a structure in which electrodes are installed at both ends of a long and thin glass tube, but such long discharge lamps are inconvenient to handle depending on the situation. For example, it has been desired to develop a small, bright discharge lamp with a short length as described in Japanese Patent Application Laid-Open No. 53-62380.

The inventors of the present invention have already made proposals in line with the above-mentioned purpose. In other words, the outline is 2
A discharge vessel with a double tube structure, with a cathode installed inside the inner glass tube, multiple anodes installed at the bottom between the outer glass bulb and the inner glass tube, and the tip of the inner glass tube corresponding to the anode. Notches were provided at the positions to form stable multi-striped discharge paths. The purpose of the present invention is to further improve this discharge lamp.

(3) Purpose of the invention In discharge lamps with double inner and outer tubes, it is difficult to fill the discharge space surrounded by the outer and inner tubes with uniform plasma. We proposed a low-pressure discharge lamp with multiple discharge paths by providing a notch. This notch at the tip of the inner tube is a process that is difficult to adapt to manufacturing of discharge lamps, especially mass production, and one of the objects of the present invention is to improve this point. The second purpose is to develop a compact low-pressure discharge lamp that has the function of increasing the illuminance on the bottom surface when actually lit and the function of improving the color of the emitted light.

(4) General description of the invention In a discharge lamp with a double inner and outer tube structure, a cathode is provided in the inner glass bulb and a plurality of anodes are provided in the outer glass bulb, and only the tip of the inner glass tube has a cross-sectional area that is equal to that of the inner glass bulb. By having an opening narrowed so that the cross-sectional area of the other part of the pipe is smaller,
The aim was to stabilize the discharge.

(5) Examples Hereinafter, the present invention will be explained in detail with reference to examples. FIG. 1 shows an embodiment of the present invention, in which the outer glass bulb 1 is a spherical glass bulb with a tube diameter of 125 mm. In addition, the inner glass bulb has a tube diameter of 30mm in length.
It has a diameter of 115 mm and has a narrow circular opening 3 at its tip. Although not shown, the inner surface of the outer glass bulb 1 and the inner and outer surfaces of the inner glass bulb 2 are coated with a phosphor. The stem 4 supports a filament cathode 5 coated with an electron-emitting material, and a flare 7 is provided in the middle of the stem 4.
The inner glass bulb 2 is adhesively fixed with an inorganic adhesive. Two anodes 6, 6' are also supported at this flare 7. The discharge tube having the above structure is exhausted by an exhaust pipe 8, and is filled with a rare gas at a required pressure and a small amount of mercury.

This discharge lamp is lit by a circuit consisting of a ballast 9, a diode bridge rectifier 10, and a glow lamp 11, as shown in the figure.

The diameters of the opening 3 at the tip of the inner glass tube 2 of the discharge lamp used in the experiment were 2.5 mm, 5 mm, 10 mm, 15 mm, and 20 mm.
One was narrow squeezed and the other was 30mm (not narrow squeezed). When 2.7 Torr of argon and mercury are filled as filler gases, all lamps with narrow apertures (2.5 mm to 20 mm) exhibit the appearance that plasma is ejected from inside the inner glass tube 2 through the aperture 3, and the outer glass bulb In the space surrounded by the inner glass tube 1 and the inner glass tube 2, two stable discharge paths were formed.

On the other hand, do not squeeze the tip of the inner glass tube (30
mm) In discharge lamps, the discharge was unstable and wavered.

In addition, the plasma ejected from the constricted aperture 3 has high brightness, and in discharge lamps with apertures of 2.5 mmφ and 5 mmφ, the brightness is approximately 10 times higher than that of plasma at the same position in discharge lamps without constricted apertures. It was confirmed that it has brightness. The position where the lamp is generally lit,
In other words, when the light is turned on at the base up position,
The tip of the discharge lamp is at the bottom, and the illuminance on the bottom surface is substantially increased, which has a great practical effect. Furthermore, when 6 Torr of neon is filled in as the filler gas, the plasma ejected from the opening 3 emits neon red light, and even in lamps using inexpensive halo phosphors, the emitted light color has a reddish tinge, giving a pleasant feeling. ing.

(6) Summary According to the present invention, in a discharge lamp consisting of a discharge vessel with an inner and outer double tube structure, by providing a narrow opening at the tip of the inner glass tube, the discharge surrounded by the outer glass bulb and the inner glass tube can be reduced. It was shown that two discharge paths were formed in space and that these discharge paths were stable. The narrow opening at the tip of the inner glass tube can be easily made by heating with a burner, for example, and there are no disadvantages when applying it to mass production.

Furthermore, in this example, the opening at the tip of the inner glass tube was circular as shown in Figure 2, but it is not necessarily limited to a circular shape, for example, it may be deformed into an almost oval shape as shown in Figure 3. There is no problem.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an embodiment of the present invention, Figure 2 is a top view of the tip of the inner glass tube of the present invention, and Figure 3 is a diagram showing an embodiment of the present invention.
The figure shows another example of the tip of the inner glass tube. 1... Outer glass bulb, 2... Inner glass bulb, 3... Narrowed opening, 4... Stem, 5...
...Cathode, 6...Anode, 7...Flare, 8...Exhaust pipe.

Claims (1)

[Claims] 1 a sealed outer glass bulb; at least a rare gas sealed within the outer glass bulb;
an inner glass tube disposed substantially coaxially within the outer glass bulb, one end of which is open and the other end closed; a cathode of
a plurality of anodes provided outside the inner glass tube and on the closed end side of the inner glass tube within the outer glass bulb, and between each of the plurality of anodes and the single cathode. In order to form a direct current discharge path where the current is shunted, only the open end of the inner glass tube is narrowed so that its cross-sectional area is smaller than the cross-sectional area of the other part of the inner glass tube. Low pressure discharge lamp.