JPS6126186B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Application of the Invention The present invention relates to a substantially spherical or cylindrical single-cap compact fluorescent discharge lamp.

(2) Prior Art The present inventors previously proposed a low-pressure steam discharge lamp as shown in FIG. In the figure, 1 is the outer glass bulb, 2 is the inner glass tube installed coaxially,
The inner and outer surfaces of the inner glass tube 2 and the inner surface of the outer glass bulb 1 are coated with a phosphor. The inner glass tube 2 is adhesively fixed at the stem 3. The stem 3 supports a filament cathode 4 coated with an electron-emitting material, and the flare of the stem 3 is
It supports anodes 5. A notch 6 is provided at the tip of the inner glass tube 2 at a position corresponding to each anode 5. Several Torr of rare gas and mercury are sealed inside the discharge lamp.

This discharge lamp is lit by a circuit consisting of a ballast 7, a full-wave rectifier 8, and a glow lamp 9. In order to equally divide the current flowing through each anode 5, a shunt 10 made of an inductance is connected.

When the discharge lamp is turned on, the current equally divided by the shunt 10 flows from each anode 5 into the discharge bulb. The plasma within the discharge bulb is formed separately between the outer glass bulb 1 and the inner glass tube 2, and between the anode 5 and the corresponding notch 6. Inside the inner glass tube 2, it becomes one plasma and reaches the cathode 4. This plasma was stable.

In order to obtain a single-cap lamp, it is desirable that the number of cap terminals be two. Therefore, it is desirable that at least the full-wave rectifier 8, the glow starter 9, and the shunt 10 be integrated with the lamp. Of the three parts mentioned above, the one that is the largest is the shunt 10 made of an inductance.

(3) Object of the Invention Therefore, the object of the present invention is to improve the above-mentioned drawbacks of the prior art, that is, to provide an alternative technique that eliminates the large shunt made of inductance.

(4) General description of the invention According to the present invention, a stable discharge path is created by controlling the branch plasma generated at the anode, that is, by providing a constricted portion between each anode between the inner glass tube and the outer glass bulb. can be formed, thus eliminating the need for a flow divider. This brings about great advantages such as miniaturization of the entire lamp, ease of manufacture, and low cost.

(5) Examples Hereinafter, the present invention will be explained in detail with reference to examples.

In the discharge lamp and lighting circuit proposed in FIG. 1, an experiment was conducted in which the two anodes 5 were short-circuited outside the discharge lamp and the shunt 10 was omitted, and the following was clarified.

In a discharge lamp without the notch 6 at the tip of the inner glass tube 2, if the shunt 10 was omitted, the plasma was unstable and continued to vibrate.

For discharge lamps with notch 6, even if there is no shunt, the two will be separated after about 10 minutes have elapsed after lighting.
A streak plasma was formed and stable. At this time, when the discharge current flowing through each anode 5 was measured, it was found that it was almost equally divided.

When the shunt 10 was omitted in the discharge lamp described above, only one line of plasma was sometimes formed for a while after lighting. Immediately after startup, two lines of plasma are formed, but plasma also begins to form between the two anodes,
When this grows, one of the main plasma rays disappears. The situation at this time is shown in Figure 2 as an exploded view of the discharge lamp. The main plasma 11 is formed between one anode 5 and the corresponding notch 6, and the branch plasma 1
2 is formed just before the anode 5 in contact with the plasma 11 and between another anode 5.

Therefore, if it is made difficult to form branch plasma 12 between the two anodes, it is expected that two stable plasma strips will be formed between each anode 5 and the notch 6 even without the flow divider 10. It was done.

FIG. 3 shows an example. In the lighting circuit, the shunt is omitted, and the positive terminal of the full-wave rectifier 8 is directly connected to the two anodes 5.

At the base of the discharge bulb, a recess 13 is provided in the outer glass bulb 1 to prevent the generation of branch plasma between the two anodes 5.

FIG. 4 is a cross-sectional view taken along the plane AA' in FIG. 3. Due to the presence of the recess 13, the distance between the outer tube bubble 1 and the inner tube glass 2 or stem 3 is narrowed between the anode 5.

In the experiment using the discharge lamp described above, two stable plasma lines were obtained without the generation of branch plasma.

The shape of the discharge lamp used in the experiment was as follows.

Inner tube and stem outer diameter 32mm Outer tube maximum outer diameter 90mm Outer tube root outer diameter 58mm External total length 170mm Inner tube notch width 17mm depth 7mm The dimensions of the recess are as follows.

Position Distance between the intermediate constricted parts of the two anodes Approximately 5 mm Length of the constricted part 10 mm or more above the anode from the root In Fig. 3, a recess 13 is provided at the root of the outer glass bulb 1, but the inner glass tube 2 or stem 3 A similar effect can be obtained by providing a convex portion in .

Further, in the above explanation, an example has been explained in which a recess is provided at the tip of the inner glass tube 2 as one of the means for forming two stripes of plasma, but the same effect can be obtained by using a partition plate instead.

(6) Summary As explained above, by adding a slight modification to the base of the discharge valve, stable discharge can be obtained without using a flow divider. This has a great effect because it can reduce the size and weight of parts that must be integrated with the discharge tube.

[Brief explanation of the drawing]

Figure 1 shows the structure of the proposed single-cap fluorescent discharge lamp, Figure 2 shows the state when only one discharge path is formed, and Figure 3 shows the structure of the discharge lamp of the present invention. FIG. 4 is a diagram showing the cross-sectional structure of the base of the discharge lamp shown in FIG. 3. 1...Outer glass bulb, 2...Inner glass tube, 3
... Stem, 4... Filament cathode, 5... Anode, 6
... cut portion, 11... main plasma, 12... branch plasma, 13... recessed portion.

Claims (1)

[Claims] 1 At least a rare gas is sealed in a discharge vessel consisting of an inner and outer double glass bubble having a structure in which an inner glass tube is provided almost coaxially within an outer glass bubble, and a cathode is arranged in the inner glass tube, and a plurality of anodes are arranged inside the inner glass tube. is installed at the base of the outer glass bubble outside the inner glass tube, and a plurality of discharge path forming parts are provided at the tip or midway of the inner glass tube at positions corresponding to each of the anodes, and A low-pressure discharge lamp characterized in that a constriction portion is provided between each of the anodes between the tube and the outer glass bubble.