JPS626304B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention improves the start-up performance of an instant-start type fluorescent lamp having a transparent conductive coating on the inner surface of the glass tube, prevents coloring and spot blackening caused by the action of the conductive coating and mercury, and maintains good luminous flux performance until the end of its life. related to maintaining a certain level of control. In instant-start type fluorescent lamps, a transparent conductive coating made of tin oxide is used on the inner surface of the glass tube as a starting support structure by setting the resistance within a certain range. These resistance ranges generally range from 60 to
The range of 500KΩ is selected because if it is over 500KΩ, the starting aid effect will be lost and it will not start.If it is below 60KΩ, the starting aid effect is extremely good, but if the transparent conductor is turned on for a long time, The coloring of the tube wall due to the action of the coating and mercury progresses from the tube end toward the center of the tube, resulting in a significant decrease in luminous flux, or the coloring of the tube wall in a width of 2 to 3 cm within a range of 10 to 30 cm from the tube end.
Dark brown band-like spots of cm in size occur. A so-called macular phenomenon is observed, and it has been known for a long time that this significantly impairs the appearance and causes a decrease in luminous flux, impairing the illumination effect. As a countermeasure against this problem, it has been proposed to provide a non-conductive film 3 such as aluminum oxide to a predetermined thickness between the transparent conductive film 2 and the phosphor layer 4, as shown in FIG. However, the non-conductive coating has no effect on the macular phenomenon, and the tube wall becomes conspicuously soiled during long-term lighting, which significantly impairs the appearance. Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, and the improvement lies in changing the composition of the sealed gas to a mixed gas containing krypton as the main component, thereby reducing the potential difference between the opposing electrodes. The objective is to eliminate the macular phenomenon and obtain good working characteristics until the end of life. The present invention will be explained in detail below using the drawings.
FIG. 1 is a partially cutaway cross-sectional view of an instant-start type fluorescent lamp.The structure of a conventional lamp with improved luminous flux operation is that a transparent conductive coating 2 made of tin oxide is coated on a glass tube 1.
is formed by laminating a non-conductive film 3 made of aluminum oxide or the like that does not easily interact with mercury, and finally a phosphor 4. In these lamps, the transparent conductive film is The resistance value over the entire length of the tube was approximately 30 to 60KΩ. In this resistance range, the starting characteristics are extremely good and stable, but during long-term lighting, the macular phenomenon 5 shown in Figure 2 occurs, and as shown by curve 8 in Figure 4, after 2000 hours. The luminous flux decreased significantly. Considering the reason for this, as shown in Figure 3, the voltage that drops across the electrodes of the lamp is approximately
115V is constantly applied to the transparent conductive coating. On the other hand, positively charged mercury ions are floating in the discharge space, which adhere to the tube wall, form one electrode, and cause a discharge between the transparent conductive coating and the tin oxide to be reduced. It is thought that tin is liberated and mercury oxide is formed, causing a dark brown macular phenomenon in this area. The present invention relates to these improvements, and specifically, as a result of various experiments, by changing the composition of the filled gas, etc., the potential difference between the opposing electrodes is set to about 100 V or less, and the transparent conductive coating and This prevents electrical discharge between the positive columns and eliminates the macular phenomenon. The effects of the present invention will be explained below with reference to Examples. EXAMPLE Table 1 shows the configuration of the sample lamps, and Table 2 shows the luminous flux working range of these lamps.

【table】

[Table] The resistance value of the transparent conductive coating made of tin oxide over the entire length of the pipe is set between 20 and 60KΩ, and alumina (Al ₂ O ₃ ), especially γ-type alumina, is applied almost uniformly to a thickness of 0.03mg on top of this. A mixture containing Kr as the main component was used to change the potential difference between opposing electrodes in a 40 Watt instant-start type fluorescent lamp in which the phosphor was applied almost uniformly to a thickness of 5 mg/ ^{cm 2 .} As a result of long-term tests of luminous flux operation and lighting appearance on gas-filled lamps, as shown in Table 2, macular phenomenon does not occur when the potential difference between opposing electrodes is 100 V or less, and the lamp remains in good condition until the end of its life. On the other hand, for lamps with a potential difference of more than 100 V between opposing electrodes, including conventional argon-filled lamps, a macular phenomenon definitely appeared, and the difference between the two was remarkable. As is clear from these results, according to the present invention, by lowering the resistance value of the transparent conductive coating, the starting characteristics are ensured and stabilized, and by using a non-conductive coating such as aluminum oxide, the tube By preventing the coloring of the entire tube wall from the ends toward the center of the tube, and by reducing the potential difference between the opposing electrodes to 100 V or less by changing the composition of the filled gas, macular phenomenon can be prevented and the end-of-life condition can be improved. It was found that the lamp exhibited good lighting appearance and luminous flux performance, and was significantly improved over conventional lamps. Regarding the resistance value of the transparent conductive film, almost the same results as shown in Table 2 were obtained even at 20KΩ or less as in the example, but when the resistance value was 100KΩ or more, the light did not turn on at low temperature startup of -10℃. Therefore, it was found that it is desirable to set the resistance to 60KΩ or less.

[Brief explanation of the drawing]

Figure 1 is a front view of an instant-start type fluorescent lamp showing a cross section with a portion cut away, Figure 2 is a diagram showing the macular phenomenon of the fluorescent lamp, and Figure 3 is the potential inside the tube of the fluorescent lamp. The diagram showing the distribution, FIG. 4, is a diagram showing the luminous flux working of the fluorescent lamp according to the invention. 1...Glass tube, 2...Transparent conductive coating, 3...
Non-conductive film, 4... phosphor, 5... macular.

Claims (1)

[Claims] 1. A 40W glass tube with electrodes at both ends, a transparent conductive coating provided on the inner surface of the glass tube with a resistance value not exceeding 60KΩ over the entire length of the tube, and a mercury provided on the conductive coating. A difficult non-conductive film, a phosphor film provided on the non-conductive film, and a phosphor film sealed in the glass tube, the main component of which is krypton, and the potential difference between the opposing electrodes exceeds 100V. and an inert gas having a gas composition such as: