JPH0745245A - Rapid start type fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a rapid start type fluorescent lamp by preventing an oxygen component from disappearing from a conductive film, suppressing its resistance value from decreasing, and preventing EC blackening and a yellow spot phenomenon. CONSTITUTION:In a rapid start type fluorescent lamp formed with a conductive film 3 in the internal surface of a glass bulb l to also provide a protective film 4 consisting of metal oxide in an internal surface of this conductive film and formed with a fluorescent material film 2 in an internal surface of this protective film, the protective film contains an oxidant 12 for presenting action of supplying oxygen. Since the protective film has the oxidant for presenting oxygen supply action, this oxidant emits oxygen, so as to burden oxygen tending to be robbed to reducing discharge space from the conductive film, and its oxygen component is prevented from decreasing, thus to prevent a resistance value of the conductive film from decreasing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instant lighting type fluorescent lamp in which a transparent conductive film is formed between the inner surface of a glass bulb and a phosphor coating.

[0002]

2. Description of the Related Art A rapid start type fluorescent lamp has a tin oxide (SnO) layer between an inner surface of a glass bulb and a phosphor coating formed on the inner surface of the glass bulb in order to improve startability.
_A transparent conductive film (EC film = nesa film) composed of ₂ ) is formed. When such an EC film is formed, this EC film acts as a conductor, and the electrons emitted from the emitter coated on the electrode during the cathode cycle propagate through the EC film near this and flow to the other electrode, and the valve is closed. Since the tube wall resistance is reduced, the lamp can be easily started, and the starting voltage can be lowered.

However, in this kind of rapid start type fluorescent lamp, excessive mercury, which has turned brown in color over a long period of time, adheres like sand scattering, and a so-called sand scattering phenomenon occurs, resulting in an external appearance. There is a flaw that damages.

It is considered that this is due to the minute discharge generated between the mercury particles in the discharge space and the EC film. That is, while the lamp is lit, mercury Hg adheres to the inner surface of the phosphor coating, and the mercury particles on the discharge space side have a potential corresponding to the discharge potential inside the tube.
The EC film is kept at a medium potential state, so that a considerable potential difference is applied between the mercury particles and the EC film via the phosphor film as an insulating material. If the phosphor coating is dielectrically broken during lighting, a slight discharge occurs,
The heat of this discharge energy melts or scatters the phosphor coating, and releases the impure gas such as oxygen contained therein. In other words, it is generally considered that the phosphor film acts as a capacitor, and the larger the amount of accumulated charge is, the larger the discharge energy in the case of dielectric breakdown is, so that mercury is oxidized (HgO) or the phosphor is Is considered to be discolored (blackening of the phosphor), the EC film is yellowing (EC blackening), and a dark brown spot pattern appears when viewed from outside the bulb.

In order to prevent such a sand scattering phenomenon, conventionally, a means for forming a protective film made of a transparent refractory metal oxide film such as alumina between the EC film and the phosphor film has been adopted. ing. That is, if a protective film such as alumina having a high resistance value is provided between the EC film and the phosphor film, the resistance between the EC film and the phosphor film becomes large, which increases the withstand voltage. Therefore, the dielectric breakdown is less likely to occur, the occurrence of minute discharge is suppressed, and the phosphor coating is not deteriorated. Therefore, the rapid start type fluorescent lamp having such a structure has an advantage that the generation of dark brown spot patterns is reduced and the luminous flux maintenance rate is improved.

[0006]

However, the rapid start type fluorescent lamp having a protective film as described above has a higher luminous flux maintenance rate than a lamp having no protective film, but it is not perfect. At the end of the life, a decrease in luminous flux maintenance factor is still observed.

With respect to this point, the inventors of the present invention have conducted various studies and experiments, and it is considered that the electric resistance value of the EC film gradually decreases with the passage of lighting time. Then, when the cause of the decrease in the electric resistance value of the EC film was estimated, it is considered that the EC film is gradually reduced and the resistance value is decreased.

That is, the discharge space of the bulb is in an oxygen-free atmosphere, that is, a reducing atmosphere. On the other hand, the EC film made of tin oxide (SnO ₂ ) is reductive and has an oxygen component on its surface. Therefore, EC
Oxygen components on the film surface are taken away by the discharge space, which causes E
The C film impairs the function as an oxide, the number of carrier electrons in the EC film increases, and the electric resistance value decreases. When the resistance value of the EC film is lowered in this manner, dielectric breakdown of the phosphor film is likely to occur, and EC blackening is likely to occur.

When manufacturing this type of fluorescent lamp, a protective film is formed on the surface of the EC film formed on the inner surface of the bulb, and a phosphor solution is applied to the surface of the protective film. Although the process of drying and baking the solution is performed, the temperature of the EC film also rises considerably in the baking process of the phosphor described above, so that the oxygen component is released from the EC film and the resistance value decreases. There is also.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the oxygen component from disappearing from the conductive film (EC film) with the passage of lighting time, and It is an object of the present invention to provide a rapid start type fluorescent lamp that suppresses a decrease in resistance value and prevents EC blackening and macular phenomenon.

[0011]

According to a first aspect of the present invention, a transparent conductive film is formed on the inner surface of a glass bulb, and a transparent protective film made of a metal oxide is provided on the inner surface of the conductive film. In a rapid start type fluorescent lamp in which a phosphor film is formed on the inner surface of the protective film and mercury and a rare gas are enclosed in the bulb, the protective film has an oxidant that has an oxygen supply function. Characterize.

The invention of claim 2 is characterized in that the oxidant is mixed in the protective film in an amount of 30 to 50% by weight of the whole. The invention of claim 3 is characterized in that the film thickness of the translucent protective film is 0.01 μm or more and 0.1 μm or less.

According to a fourth aspect of the present invention, a transparent conductive film is formed on the inner surface of the glass bulb, a transparent protective film made of a metal oxide is provided on the inner surface of the conductive film, and the inner surface of the protective film is formed. In a rapid start type fluorescent lamp in which a phosphor film is formed and mercury and a rare gas are enclosed in the bulb, a space between the conductive film and the protective film or between the protective film and the phosphor film is formed. It is characterized in that a layer having an oxidizer having an oxygen supplying action is formed therebetween.

According to a fifth aspect of the present invention, a transparent conductive film is formed on the inner surface of the glass bulb, and a phosphor film is formed on the inner surface of the conductive film, and mercury and a rare gas are sealed in the bulb. The start-type fluorescent lamp is characterized in that a layer having an oxidant having a function of supplying oxygen is formed between the conductive film and the phosphor film.

[0016] The invention of claim 6 is characterized in that the oxidant having the oxygen supplying action is at least one of CeO ₂ and Y ₂ O ₃ . The invention of claim 7 is characterized in that the layer containing the oxidant is thinner than the layer of the light-transmitting protective film.

[0016]

According to the inventions of claims 1 to 3, since the protective film formed between the conductive film and the phosphor film has an oxidant for supplying oxygen, the oxidant is oxygen. That is, the oxidant bears the oxygen component that tends to be depleted from the conductive film to the reducing discharge space, and prevents the oxygen component of the conductive film from decreasing, thus reducing the resistance of the conductive film. Prevent the value from dropping.

Further, according to the invention of claim 4 or 5, it is formed between the conductive film and the insulating protective film, or between the insulating protective film and the phosphor film, or between the conductive film and the phosphor film. The oxidant layer releases oxygen and prevents the resistance value of the conductive film from lowering.

According to the sixth aspect of the present invention, since the transparent metal oxide having the oxygen supplying action is at least one of CeO ₂ and Y ₂ O ₃ , a good oxidizing action is exhibited. According to the invention of claim 7, since the layer containing the oxidant is thinner than the layer of the light-transmitting protective film, the coloring action is regulated and the valve transmittance is kept high.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. FIG. 1 shows a straight tube type rapid start type fluorescent lamp, in which 1 is a bulb made of soda lime glass. On the inner surface of the bulb 1, a phosphor coating 2 made of, for example, a calcium halophosphate phosphor or a three-wavelength emission type phosphor is formed. A transparent conductive coating (= E) made of tin oxide (SnO ₂ ) is provided between the phosphor coating 2 and the inner surface of the bulb 1.
C film) 3 is formed. Further, between the EC film 3 and the phosphor film 2, alumina Al ₂ O ₃ , magnesia M
A protective film 4 having a high resistance and made of a transparent refractory metal oxide such as gO, titania TiO ₂ , or zinc oxide ZnO is formed. In other words, on the inner surface of the bulb 1, the EC film 3, the insulating protective film 4, the phosphor coating 2 from the bulb 1 side.
Are formed to have a three-layer structure.

The ends of the valve 1 are closed by stems 5 and 5, and electrodes 6 are attached to the stems 5 and 5. On the outside of the end of the valve 1, the base 7,
7 is worn. By the way, an oxidizing agent is mixed in the insulating protective film 4 formed between the EC film 3 and the phosphor film 2. That is, as shown in FIG. 1C, the insulating protective film 4 includes a refractory metal oxide 11 serving as a base material for insulating protection and an oxidizing agent mixed therein, such as yttrium oxide Y ₂ O. ₃ and powder 12 such as cerium oxide CeO ₂ . In this case, the mixing amount of the oxidizing agent 12 is smaller than the mixing amount of the refractory metal oxide 11, for example, the oxidizing agent 12 is mixed at a ratio of 30 to 50% by weight.

The thickness of the insulating protection film 4 is 0.01 μm.
m or more and 0.1 μm or less, and it is formed substantially uniformly over the entire valve 1. The bulb 1 is filled with a predetermined amount of mercury and a rare gas such as argon.

In the rapid start type fluorescent lamp having such a structure, the ultraviolet light emitted from mercury vapor during lighting is converted into visible light by the phosphor coating 2, and this visible light passes through the bulb 1. Is emitted to the outside.

Since the insulating protective film 4 is formed between the EC film 3 and the phosphor film 2, the resistance between the EC film 3 and the phosphor film 2 is increased, which increases the withstand voltage. Dielectric breakdown is less likely to occur. Therefore, the occurrence of slight discharge is suppressed, and the phosphor coating 2 does not deteriorate. For this reason, the generation of dark brown spots is reduced, and the luminous flux maintenance factor is improved.

Moreover, the insulating protective film 4 has an oxidizing agent 12
Since oxygen is mixed, oxygen is supplied from the oxidizer 12 to the discharge space that becomes a reducing atmosphere during lighting, and oxygen is prevented from being dissociated from the EC film 3.
That is, the oxygen that is about to be taken from the EC film 3 is supplemented by the oxidant 12, so that the oxygen existing on the surface of the EC film 3 does not disappear, and the number of carrier electrons in the EC film 3 increases. It can be suppressed. As a result, the resistance value of the EC film 3 can be kept high, the dielectric breakdown of the phosphor film 2 is prevented, and the deterioration of the EC film 3 is prevented. Therefore, the blackening of the phosphor and the occurrence of the macula are prevented, the high luminous flux maintenance ratio is maintained for a long time, and the life characteristics are improved.

In FIG. 2, the rate of change of the conductive resistance of the EC film (conductive film) was measured when alumina Al ₂ O ₃ was used as the refractory metal oxide 11 and cerium oxide CeO ₂ was used as the oxidizing agent 12. It is a graph. As shown by the solid line in FIG. 2, the rapid start type fluorescent lamp of the present invention using the insulating protective film 4 mixed with the oxidizing agent 12 has a large resistance value of the EC film 3 even after 5000 hours of lighting. No decrease was observed. On the other hand, in the case of the conventional rapid start type fluorescent lamp using the insulating protective film in which the oxidizer 12 is not mixed, the resistance value of the EC film 3 is about 1000 hours after lighting as shown by the broken line in FIG. It was measured that the initial value decreased to about 20%, and thereafter the resistance of the EC film 3 gradually decreased with the passage of lighting time.

Further, when the occurrence rate of blackening was examined, the rapid start type fluorescent lamp of the present invention showed almost no blackening even after 5000 hours of lighting as shown by the solid line in FIG. On the other hand, in the case of the conventional rapid start type fluorescent lamp, it was confirmed that the blackening gradually increased with the progress of lighting as shown by the broken line in FIG.

Further, FIG. 4 shows changes in the resistance value of the EC film 3 in each manufacturing process. As can be seen from FIG. 4, during the manufacture of the lamp, the temperature of the EC film 3 rises because the bulb is heated during the firing process and the exhaust process of the phosphor coating. In the case of the present invention, since the insulating protective film 4 is mixed with the oxidant 12, even if the valve is heated in the baking process and the exhausting process of the phosphor film, it is possible to suppress the disappearance of oxygen from the EC film 3. Therefore, as shown by the solid line in FIG.
The resistance value is prevented from decreasing. On the other hand, in the conventional lamp, when the temperature of the EC film 3 rises due to heating, oxygen is dissociated and reduced, and the electric resistance of the EC film 3 is reduced, which may cause EC blackening.

In the insulating protective film 4, the mixing ratio of the refractory metal oxide 11 and the oxidizing agent 12 is 30 to 5 when the oxidizing agent 12 is mixed.
A range of 0% by weight is preferable. That is, FIG.
5 is a graph showing the results of measuring the composition ratio of, the transmittance of the bulb, and the progress of EC blackening.
The average characteristics for 000 hours are shown. If the insulating protective film 4 is entirely composed of the metal oxide 11, the lighting time is 5000 to 8000.
The bulb transmittance after the elapse of time is good, but the luminous flux maintenance factor decreases due to the occurrence of EC blackening. On the contrary, if the insulating protective film 4 is entirely made of the oxidant 12, the lighting time is 5000 to 800.
After 0 hours, the bulb transmittance is significantly deteriorated, but EC blackening is less likely to occur, and the luminous flux maintenance factor is improved. That is, when a large amount of the oxidant 12 is mixed, the transmittance of the bulb is lowered due to the coloring effect, and when the amount is small, it is impossible to reduce the EC blackening which is the initial purpose. As can be understood from FIG. 5, the oxidizing agent 12 is preferably mixed in the range of 30 to 50% by weight based on the whole amount.

FIG. 6 is a graph showing the results of examining the film thickness of the insulating protective film 4 in relation to the transmittance of the valve. When the thickness of the protective film 4 exceeds 0.1 μm, the transmittance of the valve is lowered due to the coloring effect, and when it is less than 0.01 μm, the function of the protective film 4 is impaired. Therefore, the thickness of the protective film 4 is preferably in the range of 0.01 to 0.1 μm.

2 to 6 is an example of a lamp using alumina Al ₂ O ₃ as the refractory metal oxide 11 and cerium oxide CeO ₂ as the oxidant 12. Refractory metal oxide 11 and oxidizer 1
Various cases can be used for the combination of two, and for example, the case shown in Table 1 below may be used.

[0031]

[Table 1]

In the above embodiment, the case where the oxidizing agent 12 is mixed with the insulating protective film 4 has been described, but the oxidizing agent may be provided separately from the insulating protective film 4. That is, in the example of FIG. 7, an oxidant layer 20 made of yttrium oxide Y ₂ O ₃ or cerium oxide CeO ₂ is formed between the EC film 3 and the insulating protective film 4, and FIG. In this example, an oxidizer layer 20 made of yttrium oxide Y ₂ O ₃ or cerium oxide CeO ₂ is formed between the insulating protective film 4 and the phosphor film 2. In this case, the oxidizer layer 20 is thinner than the insulating protective film 4.

Even with the configuration shown in FIG. 7 or FIG.
Since the oxidant layer 20 has a function of supplying oxygen, oxygen in the EC film 3 is not lost, and a decrease in electric resistance can be prevented. In this case, the layer 20 with oxidant
Has a thickness smaller than that of the translucent protective film 4,
The coloring effect is regulated, and the valve transmittance can be kept high.

Further, the present invention is not necessarily limited to the rapid start type fluorescent lamp having the insulating protective film 4 formed thereon. In other words, it has been found that one cause of EC blackening is the disappearance of oxygen from the EC film 3. Therefore, it can be applied to a rapid start type fluorescent lamp having a structure in which the insulating protective film 4 is not formed. . For example, FIG. 9 shows a rapid start type fluorescent lamp having no insulating protection film 4, in which case an EC film 3 is provided on the inner surface of the bulb 1.
The oxidizer layer 20 is formed directly on the inner surface of the EC film 3, and the phosphor coating 2 is provided on the inner surface of the oxidizer layer 20. Even with such a structure, it is possible to suppress the disappearance of oxygen from the EC film 3 in the oxidant layer 20 and prevent the resistance value from decreasing.

[0035]

As described above, according to the first to third aspects of the present invention, the protective film formed between the conductive film and the phosphor film has an oxidant that exhibits an oxygen supplying action. Therefore, this oxidant releases oxygen, that is, the oxidant bears the oxygen component that is about to be deprived from the conductive film into the reducing discharge space, and prevents the oxygen component of the conductive film from decreasing. Therefore, the resistance value of the conductive film is prevented from lowering. Therefore, it is possible to prevent the EC blackening and the macular phenomenon and increase the luminous flux maintenance factor.

Further, according to the invention of claim 4 or 5, it is formed between the conductive film and the insulating protective film, or between the insulating protective film and the phosphor film, or between the conductive film and the phosphor film. The oxidant layer releases oxygen and prevents the resistance value of the conductive film from lowering.

According to the sixth aspect of the present invention, since the transparent metal oxide having the oxygen supplying action is at least one of CeO ₂ and Y ₂ O ₃ , a good oxidizing action is exhibited. According to the invention of claim 7, since the layer containing the oxidant is thinner than the layer of the light-transmitting protective film, the coloring action is regulated and the valve transmittance is kept high.

[Brief description of drawings]

FIG. 1 shows a rapid-start type fluorescent lamp showing an embodiment of the present invention, FIG.
(B) is an enlarged cross-sectional view of portion B of (A),
FIG. 6C is an enlarged cross-sectional view of the portion C of FIG.

FIG. 2 is a characteristic diagram showing a ratio of a lighting time and a resistance change of a conductive film.

FIG. 3 is a characteristic diagram showing a lighting time and a blackening occurrence rate of a bulb.

FIG. 4 is a characteristic diagram showing a relationship between a lamp manufacturing process and a change in resistance value of a conductive film.

FIG. 5 is a characteristic diagram showing the relationship between the composition ratio of the protective film, the transmittance of the bulb, and the degree of EC blackening.

FIG. 6 is a characteristic diagram showing the relationship between the film thickness of a protective film and the transmittance of a valve.

FIG. 7 is an enlarged cross-sectional view of a main part showing a second embodiment of the present invention.

FIG. 8 is an enlarged cross-sectional view of a main part showing a third embodiment of the present invention.

FIG. 9 is an enlarged cross-sectional view of a main part showing a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bulb 2 ... Fluorescent substance film 3 ... Transparent conductive film (conductive film) 4 ... Insulating protective film 6 ... Electrode 11 ... Refractory metal oxide 12 ... Oxidizing agent 20 ... Oxidizing agent layer.

Claims (7)

[Claims] 1. A transparent conductive film is formed on the inner surface of a glass bulb, a light-transmitting protective film made of a metal oxide is provided on the inner surface of the conductive film, and a phosphor film is formed on the inner surface of the protective film. A rapid-start type fluorescent lamp which is formed and has mercury and a rare gas enclosed in the bulb, wherein the protective film has an oxidant that supplies oxygen. 2. The oxidant is contained in the protective film in a total amount of 30%.
The rapid start type fluorescent lamp according to claim 1, wherein the fluorescent lamp is mixed in a ratio of about 50% by weight. 3. The transparent protective film has a thickness of 0.01 μm.
It is above 0.1m, It is characterized by being below.
Alternatively, the rapid start type fluorescent lamp according to claim 2. 4. A transparent conductive film is formed on the inner surface of a glass bulb, a light-transmitting protective film made of a metal oxide is provided on the inner surface of the conductive film, and a phosphor film is formed on the inner surface of the protective film. In a rapid start fluorescent lamp in which mercury and a noble gas are enclosed in the bulb formed, oxygen of oxygen is formed between the conductive film and the protective film or between the protective film and the phosphor film. A rapid-start type fluorescent lamp, characterized in that a layer having an oxidizing agent having a supply function is formed. 5. A rapid-start type fluorescent lamp in which a transparent conductive film is formed on the inner surface of a glass bulb, and a phosphor film is formed on the inner surface of the conductive film, and mercury and a rare gas are sealed in the bulb. 3. A rapid-start type fluorescent lamp, wherein a layer having an oxidant having an oxygen supply function is formed between the conductive film and the phosphor film. 6. The oxidant, which has the function of supplying oxygen,
7. The rapid start type fluorescent lamp according to claim 1, wherein the rapid start type fluorescent lamp is at least one of CeO ₂ and Y ₂ O ₃ . 7. The rapid start type fluorescent lamp according to claim 3, wherein the layer containing the oxidant is thinner than the layer of the translucent protective film.