JPS6347103B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a compact fluorescent lamp having a double tube structure in which a bent inner tube is housed in a discharge space formed by an outer tube and a button stem.

Against the background of energy conservation in recent years, in the field of light sources, we are using the principles of optical lamps, which have the great advantages of high efficiency and long life, to replace incandescent light bulbs, which have the fatal disadvantages of low efficiency and short life. Fluorescent lamps with a transparent and compact structure are being actively studied.

In line with this trend, the present application was previously filed for a compact fluorescent lamp having a structure as shown in FIG. That is, the outer tube 1 and the button stem 2
A fluorescent lamp in which two U-shaped inner tubes 4 are housed in a discharge space 3 kept airtight by
A phosphor 5 is coated on the inner surface of the U-shaped inner tube 4, and one end of the inner tube 4 is hermetically fixed around an electrode 6, and the other open end 7 is used to connect both electrodes. Discharge occurs between 6 and 6. In addition, in the figure, 8 is a lighting device part, and 9 is a screw cap.

However, the above-mentioned compact fluorescent lamp has the following problems in its performance. In other words, since the above-mentioned lamp has a double tube structure, the temperature of the inner tube (including the U-shaped inner tube 4 and internal parts of the lamp) does not rise sufficiently during baking during the exhaust process during lamp manufacturing. Due to the multi-tube structure, heat transfer to the inner tube is poor, and heating baking from the outside creates a large temperature difference between the outer tube 1 and the inner tube).Therefore, the exhaust efficiency is poor, and a large amount of adsorbed impurity gas is trapped inside. The lamp will be tipped off leaving it in the tube. Of course, if the evacuation time is greatly increased, the temperatures of the outer tube 1 and the inner tube will gradually approach each other and the desired evacuation efficiency can be obtained, but this operation is not preferable in terms of manufacturing efficiency, cost, etc.

As a result, due to the influence of residual impurity gas, There is significant blackening of the tube wall near the electrode 6.

The luminous flux attenuation rate of the phosphor 5 is large.

Lamp life is short.

There were problems such as.

The present invention was devised in view of these drawbacks, and an object of the present invention is to provide a fluorescent lamp with improved performance by improving the exhaust process.

Hereinafter, the present invention will be explained based on illustrated embodiments. FIG. 2 is a perspective view showing the lamp section of the fluorescent lamp according to the present invention, and FIG. 3 is an enlarged cross-sectional view of the inner tube, which has almost the same structure as the conventional one. In the manufacturing process, first, SnO ₂ is applied to the inner or outer wall of the inner tube 4.
(tin oxide) film or In ₂ O ₃ (indium oxide)
A transparent infrared selective absorption film 10 made of a film or the like is formed, and then a phosphor 5 is applied to the inner wall of the inner tube 4.
Fire and coat. Next, the inner tube 4 is placed around the electrode 6 on the button stem 2 by a method such as gluing or sealing. Then attach outer tube 1 to button stem 2
The exhaust pipe 11 is connected to an exhaust system (not shown) to exhaust the interior of the lamp, which is kept airtight by the sealed outer tube 1 and button stem 2. The inside of the chamber is evacuated to vacuum, and a gas furnace is used to heat the chamber with a gas flame. At this time, the outer tube 1 is heated by the gas flame, and since the inner tube 4 is also coated with the infrared absorbing film 10, the temperature is increased by the gas flame, and the exhaust efficiency is improved compared to the conventional method. Next, the electron radioactive material applied to the electrodes 6 is activated, and a predetermined amount of mercury and inert gas are sealed, and then the exhaust pipe 11 is tipped off to complete the lamp.

Note that heating with the gas furnace is performed continuously until just before the mercury and inert gas are filled. Further, in this embodiment, a lamp consisting of two U-shaped inner tubes 4 has been described, but the present invention can be applied regardless of the number and shape of the inner tubes 4.

As mentioned above, the transparent infrared selective absorption film 10 is applied to the inner or outer wall of the inner tube 4, and the inner tube 4 is also heated and heated in a gas furnace during the exhaust process, thereby significantly reducing the residual impurity gas inside the lamp. As a result, an improved fluorescent lamp as described below could be obtained.

(1) As shown in Figure 4, blackening of the tube wall near the electrodes was significantly suppressed ( _A1 in the figure is the measured value with the lamp according to the present invention, B is the measured value with the conventional product, The blackening rate on the vertical axis indicates that level 5 is no blackening, and the smaller the number, the greater the blackening.) (2) The luminous flux attenuation rate of the phosphor 2 has been improved. (See Figure 5) (3) Lamp life has been improved from about 4,000 hours to about 5,000 hours. (See FIG. 5) (In FIG. 5, A ₁ is a measured value using the lamp according to the present invention, and B is a measured value using a conventional product.) Next, different embodiments of the present invention will be described. The difference from the previous embodiment is that the outer tube 1 was also coated with a transparent infrared selective absorption film like the inner tube 4, and an infrared oven was used for baking during evacuation. As a result, as shown by A ₂ in Figures 4 and 5,
It was possible to obtain a fluorescent lamp that was improved over the previous example in both the blackening rate and the lifespan.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional fluorescent lamp, FIG. 2 is a perspective view showing a lamp part of a fluorescent lamp according to the present invention, and FIG. 3 is an enlarged sectional view of the inner tube wall of the same.
Figure 4 is a graph showing the blackening rate of the tube wall near the electrode.
FIG. 5 is a graph showing the luminous flux attenuation rate and lamp life.

Claims (1)

[Claims] 1. In manufacturing a fluorescent lamp with a double tube structure in which a bendable inner tube is housed in a discharge space formed by an outer tube and a button stem, and the inner tube serves as a discharge path,
At least a transparent infrared selective absorption film is formed on the tube wall of the inner tube in advance, and baking during the exhaust process is performed using gas furnace heating or infrared furnace heating, and the inner tube is heated at the same time as the outer tube. Features: A manufacturing method for fluorescent lamps.