JPS59177849A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To prevent any light and darkness flickering from being caused even after long-period burning by specifying the diameter of a filament to be 0.070- 0.076mm. in a fluorescent lamp in which a double coil filament is sealed and which has a lamp current of 0.30-0.40A. CONSTITUTION:In a fluorescent lamp having a rated power of 20W and a lamp current of 0.30-0.40A, leg portions 2 consisting of a primary coil formed by winding a tungsten wire 1 by means of lead wires 5. The primary coil is wound into a secondary coil 3, while is then coated with an electron-discharging matter. The diameter of the wire 1 is 0.070-0.076mm.. As a result, a fluorescent lamp in which no light and darkness flickering is caused even after long-period burning, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to prevention of flickering in brightness of a fluorescent lamp sealed with a double coil filament, and particularly to prevention of flickering in brightness of a fluorescent lamp sealed with a double coil filament.
．． Suitable for 30-0.4OA, rated 20W type.

[Technical background of the invention and its problems]

It is well known that when a fluorescent lamp is lit on an AC circuit, the light fluctuates near the filament at a frequency twice the power supply frequency, which can be perceived as flickering. That is, this is felt because there is a difference in light output when the electrode is a cathode and an anode. Normally, this flickering does not cause much discomfort, but when a small output lamp with a rated output of 20 W is lit for a long time, an unpleasant flickering may occur near the electrodes. The reason for this is that the anode vibration, that is, the repeated phenomenon of ion generation and extinction due to rapid ionization in the anode region, no longer occurs regularly, and as a result, it is felt as a flicker in brightness.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluorescent lamp which does not flicker between brightness and darkness even when it is operated for a long period of time, even when it is completely equipped with a double coil filament.

[Summary of the invention]

By limiting the filament diameter to a certain range, the temperature of the electrode is lowered, thereby regularizing the vibration of the anode.

[Embodiments of the invention]

The present inventors measured the filament temperature of a 20W rated fluorescent lamp that had been operated for a long period of time when flickering was occurring, when anode vibration was occurring and when it was not occurring, and calculated the relationship between flickering and temperature. I found all the correlations. First, the structure of the filament is shown in FIG. (1) is a tungsten wire, (2) is a leg part consisting of a primary coil made by fully winding this tungsten wire (1), (3) is a secondary coil part made by further winding a secondary coil, (4) is a The boundary of the rabbit radioactive material deposited on this secondary coil part (3), (5)
is a lead wire that supports the leg portion (2). and,(
, (B>, (C), (D), (E), (F), (Gl
l'i is the temperature measurement point. Then, the distance measurement result f
It is shown in Figure 2. In the figure, the horizontal axis shows the measurement points in their order, and the vertical axis shows the measured temperature in °C.
″l is the temperature of each part when the anode vibration disappears, the curve [10
indicates the temperature of each part when anode vibration occurs.

From this figure, it was found that when the anode vibration disappeared, the temperature was about 100°C higher than when it occurred. From this fact,
Assuming that the temperature of the current filament is in the critical region where anode vibration occurs and disappears, if the filament temperature is lowered by some means, the anode vibration will always occur regularly, resulting in brighter light. I was led to believe that it would be possible to prevent the flickering of light. As a means of lowering the temperature, it is effective to improve heat conduction to the lead wires and increase heat preservation, so we changed the filament wire diameter and coil pitch in various ways to reduce flickering in brightness. We investigated whether this would occur.

First, let's take a look at the FL20SSW/1 as an example of a fluorescent lamp.
8, and the design values of the filament are shown in Table 1 below.

This fluorescent lamp was lit for a long period of time at 0.30-Q, 32A, which is close to the lower limit of the rated tube current of a 20W type, and the flicker occurrence rate was investigated. The results are shown in Table 2 below.

Table 2 From this Table 2, it was found that increasing the wire diameter of the filament is effective in preventing flickering, and that the pitch has almost no effect within the practical range.

It has also been found that flickering does not occur when the filament wire diameter is 0.068ii or more when the tube current is in the range of 0.30 to 0.32. However, it was also found that when the wire diameter is 0.080 mm or more, end glow is difficult to occur when starting the lamp, and it is not practical in terms of starting at low temperatures.

Next, this lamp was lit for a long period of time at 0.38 to 0.4 OA, which is close to the upper limit of the rated tube current value of a 20W type, and the flicker occurrence rate was investigated. The results are shown in the following 81!3 table.

(Jυ, Lower Zenzan) 3rd Cloth From Table 3, the wire diameters are 0.070mm and 0.07mm.
It was found that 61 was effective, the pitch had no effect in the practical range, and o and oso were low temperature starters and were not practical. From both results, the lamp current is 030~0.4O.
In a water source lamp with a rating of 20 V/A, it was found that by setting the wire diameter of the filament to 0.070 to 0.076 ynm, a flicker-free and practical electric lamp could be obtained. did.

〔Effect of the invention〕

The uninvented fluorescent lamp is equipped with a double coil filament, and the wire diameter of this filament is 0.070.-0076N.
N, heat transfer from the filament to the lead wire increases, the filament temperature decreases, and the anode vibration of the filament is always carried out regularly, resulting in a firefly that does not flicker between bright and dark even when lit for a long time. A light lamp is obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a filament of an embodiment of the fluorescent lamp of the present invention, and FIG. 2 is a temperature distribution diagram showing the temperature of each part of this filament in comparison with that of a conventional one. (1) - Tungsten wire (2) - Leg part (3) -,
Secondary coil section

Claims (1)

[Claims] Lamp current 0 with sealed double coil filament
．． A fluorescent lamp of 30 to 0.4 OA, characterized in that the filament has a wire diameter of 0.070 to 0.076 mm.