JPS61248339A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To remove alumina solution accumulated at the lower end of a glass tube effectively, and prevent deterioration of the lamp and a poor mount sealing, by spreading alumina solution at the inner surface of the glass tube for a fluorescent lamp, and then pouring an adequate amount of water at the lower end of the glass tube while the alumina is being dried. CONSTITUTION:After the inside of a glass tube is washed, an alumina suspension is spread, and when almost all portions are dried, some undried liquid 3 remains at the inner lower end of the glass tube 2. If a phosphor solution is spread while the remaining liquid is left as it is, alumina is mixed in the phosphor solution, resulting in an unfavorable deterioration of luminous flux maintaining rate during the lamp lighting. Therefore, by pouring water through a nozzle 5 or the like from the outside of the glass tube 4, undried alumina solution at the inner lower end of the glass tube 4 and alumina at the outer lower end of the tube 4 can be washed out efficiently and in a low cost.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for manufacturing a fluorescent lamp having an alumina layer, and is particularly suitable for reducing the defective rate during manufacturing of fluorescent lamps or improving the quality of fluorescent lamps. Regarding the method.

[Background of the invention]

A method similar to the present invention is described in JP-A-58-166623. However, this is limited to the removal of the phosphor coating applied to the inner surface of the fluorescent lamp, and does not address the optimum flow rate.

[Purpose of the invention]

The purpose of the present invention is to prevent alumina applied to the inner surface of the glass tube from adhering to the inner and outer surfaces of the lower end of the glass tube and mixing into the phosphor coating liquid applied as the second layer, resulting in deterioration of the characteristics of the fluorescent lamp.
It is an object of the present invention to provide a method for manufacturing a fluorescent lamp that can reduce sealing defects when sealing electrode parts to both ends of a glass tube.

[Summary of the invention]

For this purpose, after applying an alumina suspension to the entire inner surface of the glass tube by spraying or falling coating, during the drying process, an appropriate amount of water is poured around the outside of the glass tube using a nozzle, etc. to coat the inner and outer surfaces of the lower end of the glass tube. It is designed to locally and efficiently wash away adhered alumina.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to the drawings.

A conductive coating (
It is well known that in a rabbit-start type fluorescent lamp formed with a coating (NESA film), if the resistance value of the film is small, the discharge starting voltage will be low, and conversely, if it is high, it will not easily turn on. Therefore, it is necessary to form a coating having an appropriate resistance value. However, this coating is mainly composed of tin oxide, and when the lamp is left on for a long time, it forms a compound with the mercury sealed inside the lamp, resulting in rapid deterioration of the luminous flux.

In order to compensate for this drawback, a method has been adopted in which a thin film of alumina is formed as the first layer.

After cleaning the inner surface of the glass tube, an alumina suspension is applied and the entire surface is dried. In this state, as shown in FIG. 3 remains. If the phosphor coating liquid is not applied with this liquid portion 3 remaining, alumina will be mixed into the phosphor coating liquid, which will undesirably lower the luminous flux maintenance rate during the operation of the fluorescent lamp. Furthermore, even if this undried portion is dried, not only will energy costs increase, but alumina will solidify, spoiling the appearance, and the alumina adhering to the bottom end of the glass tube 2 must be sealed to seal the electrodes to both ends of the glass tube 2. This may cause poor sealing during the process.

Therefore, in the present invention, in the alumina coating liquid drying process,
As shown in FIG. 2, by flowing water 6 from the outside of the glass tube 4 using a nozzle 5 or the like, the undried alumina liquid on the inner surface of the lower end of the glass tube 4 or the alumina on the outer surface of the lower end of the glass tube 4 can be efficiently and inexpensively removed. was able to be washed.

The amount of water required for cleaning is, for example, FL-40s (32φ pipe).
At approximately 200 to 500 ca/min per nozzle, the alumina liquid accumulated at the lower end of the glass tube 4 is reliably removed by cleaning 2 to 5 heads for 4 to 10 seconds. I was able to do that. The inner diameter of the nozzle is approximately 5
mφ is appropriate. Note that 7 is a valve and 8 is a flow meter.

〔Effect of the invention〕

As described above, the present invention makes it possible to effectively remove the alumina liquid that accumulates at the lower end of the glass tube during alumina coating. As a result, deterioration in the characteristics of the fluorescent lamp and poor mount sealing can be suppressed, and a good fluorescent lamp can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a dry state after applying an alumina coating liquid to the inner surface of a glass tube, and FIG. 2 is a side view according to the present invention for cleaning alumina on the inner and outer surfaces of the lower end of the glass tube. 1... Alumina coating film, 2... Glass tube, 3...
Alumina liquid accumulated at the lower end of the glass tube, 4... Fluorescent Lang glass tube, 5... Nozzle for flowing water, 6...
Washing water, 7... Pulp for adjusting the flow rate of washing water discharged from the nozzle, 8... Flow meter for controlling the flow rate. Ivy 1

Claims (1)

[Claims] 1. Alumina (AlO
After applying the coating solution of _2), an appropriate amount of water is allowed to flow down the lower end of the glass tube during the drying process of the alumina to remove alumina accumulated at the lower ends of the inner and outer surfaces of the glass tube. Method of manufacturing light lamps.