JPH05290812A - Rapidly starting type fluorescent lamp - Google Patents

Abstract

PURPOSE:To provide a rapidly starting type fluorescent lamp having an improved starting characteristic and capable of preventing blakening of a phosphor and an EC film due to fine electric discharge. CONSTITUTION:In a rapidly starting type fluorescent lamp where a transparent conductive film 20, an aluminum protecting film 21 made of transparent metal oxide and a phosphor coating film 22 are laminated on the inner surface of a bulb 10, a portion 25 where neither the protecting film made of metal oxide nor the phosphor coating film are formed but only an EC film is formed is provided in the vicinity of an electrode 12 on the inner surface of the bulb. Accordingly, since the EC film is exposed to the inner surface of the bulb in the vicinity of the electrode, tube wall resistance of the bulb can be reduced so that starting of the lamp can be facilitated. Moreover, because electric charge can escape to the EC film from the portion where the EC film is exposed, a potential difference between mercury and the EC film can be decreased, thus preventing fine electric discharge and blackening of the phosphor coating film and the EC film.

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 fluorescent lamp is a transparent conductive film made of tin oxide or the like between an inner surface of a glass bulb and a phosphor coating formed on the inner surface in order to improve startability. (EC film = nesa film) is formed.
When such an EC film is formed, this film acts as a conductor, and 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 Since the tube wall resistance is lowered, the lamp can be easily started, and the starting voltage can be lowered.

However, in this type of rapid-start fluorescent lamp, excess mercury, which has turned a brown color with use for a long time, adheres like sand scattering, and a so-called sand scattering phenomenon occurs, resulting in an 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 on, 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.
Since the EC film is kept at a medium potential state, a considerable potential difference is applied between these mercury particles and the EC film via the phosphor film as an insulating substance, and this phosphor film is It is considered that when dielectric breakdown occurs due to the above potential difference, a slight discharge occurs, and the heat of this discharge energy causes the phosphor coating to dissolve, scatter, or release an impure gas such as oxygen contained therein. In other words, it is 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 Discoloration (blackening of the phosphor), yellowing of the EC film (EC
It is considered that a dark brown spot pattern appears when viewed from outside the bulb.

In order to prevent such a sand scattering phenomenon, E
It is considered to form a protective film made of a transparent refractory metal oxide film such as alumina between the C film and the phosphor film. That is, when an alumina protective film having a high resistance value is interposed between the EC film and the phosphor film, EC
The resistance between the film and the phosphor coating increases, which increases the withstand voltage, so that dielectric breakdown is less likely to occur, and thus 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 brownish brown spot patterns is reduced and the luminous flux maintenance rate is improved.

[0006]

However, the EC film is originally provided for the purpose of functioning as a conductor for lowering the wall resistance of the valve, and the insulating protective film is formed as described above. If the resistance is increased, the valve wall resistance of the valve increases, and it becomes difficult to start the valve. Therefore, it is necessary to apply a rather high voltage at the time of starting, and the original purpose of improving the starting characteristics cannot be achieved.

Further, when such a protective film is formed,
It is possible to lengthen the time when the spots start to be generated as a whole as compared with the case without the protective film, but since the potential difference between the electrode and the EC film becomes large in the vicinity of the electrode, dielectric breakdown occurs at this portion, and therefore the electrode The problem that a dark brown spot pattern is concentrated in the vicinity remains.

Therefore, it is conceivable to form a region in which a protective film is not formed near the electrode and lower the withstand voltage in this region to improve the starting performance. However, in this case, since the region where the protective film is not formed is formed by laminating the phosphor film on the EC film, it becomes the same as the lamp of the first structure where the protective film is not formed after all, and a brown spot pattern is formed. Occurs.

The present invention has been made in view of the above circumstances. An object of the present invention is to improve the startability and prevent deterioration of the fluorescent substance and the EC film due to a slight discharge so that dark spots of brown color can be obtained. The present invention is intended to provide a rapid start type fluorescent lamp that can prevent the occurrence of such problems.

[0010]

According to the present invention, a transparent conductive film (EC film) is formed on the inner surface of a glass bulb having electrodes sealed at its ends.
And a protective film made of a transparent metal oxide is provided on the inner surface of the EC film, and a phosphor film is formed on the inner surface of the protective film of the metal oxide, and mercury is enclosed in the bulb. In the rapid start type fluorescent lamp,
A feature of the present invention is that a portion where the protective film of the metal oxide and the phosphor coating are not formed is provided on the inner surface of the bulb near the electrode, and only the EC film is formed at this portion.

[0011]

According to the lamp of the present invention, since the EC film is exposed on the inner surface of the bulb in the vicinity of the electrode, the insulation resistance between the electrode and the EC film becomes small, and one electrode and the other electrode respectively have a discharge space. It becomes easy to be electrically connected to the EC film directly via the electric field, so that the tube wall resistance of the bulb becomes low, and thus the starting of the lamp becomes easy. In addition, since the insulation resistance is kept high in the area where the EC film is not exposed, not only is the occurrence of minute discharge prevented, but the EC film is exposed even if the amount of charge accumulated in the phosphor film increases. The electric charge escapes from the portion to the EC film, and the potential difference between the mercury Hg adhering to the phosphor film and the EC film becomes lower than the threshold value of the dielectric breakdown, thus preventing a slight discharge, It is possible to prevent spots from being formed on the phosphor coating or the EC film.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. 1 and 2 show a straight tube type rapid start type fluorescent lamp, and 10 is a bulb made of soda lime glass. Valve 10
Both ends of the are sealed by the stems 11 and 11. The stems 11 and 11 have electrodes 1 made of filaments.
2, 12 are attached. Filament 12, 12
Are laid over the wells 13 and surrounded by a shield ring 14 holding a mercury alloy. The filaments 12, 12 are coated with a Ba-based emitter such as barium oxide, and the shield ring 14 holds a mercury-releasing alloy (not shown). The emitters scattered from the filaments 12, 12 are prevented from adhering to the bulb wall.

A cap 1 is provided at each end of the valve 10.
5 and 15 are attached to the bases 15 and 15, and the base pins 1 connected to the wells 13 and 13 are attached to the bases 15 and 15.
6 and 16 are projected.

A transparent conductive film (EC film = nesa film) 20 made of tin oxide or the like is formed on the inner surface of the valve 10. The inner surface of the EC film 20 is made of alumina Al ₂ O ₃ ,
An insulating protective film 21 made of a transparent refractory metal oxide such as magnesia MgO or titania TiO ₂ is formed.
A phosphor coating 22 made of, for example, a calcium halophosphate phosphor is formed on the inner surface of the insulating protective film 21. That is, on the inner surface of the bulb 10, the EC film 20, the insulating protective film 21, and the phosphor coating 22 are formed in a three-layer structure from the bulb 10 side. As a general rule, these coatings are formed on the entire inner surface of the bulb 10. It is formed over.

However, the insulating protective film 21 and the phosphor film 22 are not formed on the inner surface of the bulb 10 which is located in the vicinity of the electrodes 12, 12 and slightly closer to the center of the discharge space than the electrodes 12, 12. A portion 25 in which only the EC film 20 is simply formed is provided on the above. In other words, the insulating protective film 21 and the phosphor coating 22 are peeled off near the electrodes to remove the EC.
A region 25 is formed in which only the film 20 is formed. The portion 25 where the insulating protective film 21 and the phosphor coating 22 are not formed is formed, for example, in a rectangular shape or a circular shape along the wall surface of the bulb 10. The area of this portion 25 is 25 mm ²
It is set as described above. The valve 10 is filled with a rare gas such as argon.

The operation of the rapid start type fluorescent lamp having such a structure will be described. When the lamp starts,
When a starting voltage is applied between the filaments 12 on both ends of the bulb, electrons are emitted from the emitter of the filament 12 serving as a cathode, and the electrons propagate to the EC film 22. In this case, as shown in FIG. 3, a region 25 is formed near the electrode in which the insulating protective film 21 and the phosphor coating 22 are peeled off to form only the EC film 20, that is, the EC film 20 is exposed to the discharge space. Therefore, the probability of electrons jumping directly into the EC film 20 increases, and the electrons flow to the other electrode through the EC film 20. Also in the other electrode, electrons flow to the electrode from the region 25 in which only the EC film 20 formed in the vicinity is formed. Therefore, the electric conductivity at the time of starting is improved, and the main discharge between the electrodes 12 can be generated without increasing the starting voltage particularly. That is, compared with the case where the insulating protective film 21 and the phosphor coating 22 are formed on the inner surface of the EC film 20, the insulating protective film 21 and the phosphor coating 2 are provided.
In the case without 2, the EC film 20 does not hinder the conduction between the electrodes 12, so that the EC film 20 exerts a good conductive action, and therefore, the starting becomes easier and the starting voltage can be lowered.

On the other hand, during steady lighting, it can be considered that mercury Hg is attached to the inner surface of the phosphor coating 22, and the mercury particles on the discharge space side are applied with a potential corresponding to the discharge potential in the tube. On the other hand, the EC film 20 maintains a medium potential state. Therefore, when the insulating protective film 21 and the phosphor coating 22 are present between the mercury particles and the EC film 20, the insulating resistance of the insulating protective film 21 and the phosphor coating 22 causes the resistance between the mercury particles and the EC film 20. A considerable potential difference acts between them. When the charge accumulation amount of mercury particles exceeds the insulation resistance of the insulating protective film 21 and the phosphor film 22, that is, when the withstand voltage is exceeded, dielectric breakdown occurs, and a slight discharge occurs between the mercury particles and the EC film 20. Due to the heat of this discharge energy, the phosphor film is dissolved or scattered, and the EC film is yellowed. Particularly, in the vicinity of the electrode 12, the mercury particles and the E
Since the potential difference between the C film 20 and the
Blackening of the film is likely to occur.

However, in the case of the present embodiment, the insulating protective film 21 and the phosphor coating 22 are peeled off near the electrodes, and EC is removed.
Since the region 25 in which only the film 20 is formed is provided, the mercury particles directly contact with the EC film 20 in this region 25, so that no charge is accumulated in the mercury particles. Therefore, in the region 25 where only the EC film 20 is formed, a slight discharge between the mercury particles and the EC film 20 does not occur. Therefore, the phosphor film 22 and the EC film 2
There is no deterioration of 0.

In addition, in regions other than the region 25 where only the EC film 20 is formed, the insulating protective film 21 and the phosphor film 22 are formed, the mercury Hg adhering to the inner surface of the phosphor film 22 is charged. Even if it is charged, it is bypassed by the mercury particles adhering to the region 25 where only the EC film 20 is formed, and the electric charge is released to the EC film 20. Therefore, even if mercury Hg is charged in the region where the insulating protective film 21 and the phosphor coating 22 are formed, the charge accumulation amount is small, which is the threshold for the dielectric breakdown of the insulating protective film 21 and the phosphor coating 22. Since it is kept below the value, a slight discharge does not occur in these regions. That is, the insulation resistance of the insulation protection film 21 is effectively used in regions other than the region 25 in which only the EC film 20 is formed, and the occurrence of minute discharge is prevented.

From the above, the oxidation of mercury (Hg
O), discoloration of the phosphor (blackening of the phosphor), and yellowing of the EC film (EC blackening) are prevented or reduced, and a dark brown spot pattern seen from outside the bulb is prevented. Can
The luminous flux maintenance factor can be improved.

The results of experiments of the present invention will be described.
That is, Table 1 shows a straight tube type rapid start type fluorescent lamp having the structure shown in FIG. 1 and FIG.
SW / M / 36) shows the results of measuring the size (notch area) of the region 25 in which the insulating protective film 21 and the phosphor film 22 are notched, the lighting time, and the degree of occurrence of EC blackening. It is a thing. The degree of occurrence of EC blackening was evaluated visually by several inspectors, and the score was set to a 10-point evaluation formula, and in the case of 10 points, it was a non-defective product in which blackening did not occur.

[0022]

[Table 1]

From the above results, it can be understood that the EC blackening can be reduced and the luminous flux maintenance factor can be improved by forming the cutout portion 25. In addition, the area S of the notch 25 is set to 25
mm ² With the above settings, no blackening of EC was observed even after the lighting time exceeded 10,000 hours, confirming the effect of the present invention.

Further, FIGS. 4 to 7 are views showing blackening occurrence states in lamps having various structures, and these figures are transcribed from photographs. As is apparent from the display mark, each lamp is a FLR40SW / M / 36 type rapid start fluorescent lamp, and has been in a state of 1000 hours of lighting.

In the lamp shown in FIG. 4, the EC film 20, the insulating protective film 21, and the phosphor film 2 are formed on the entire inner surface of the bulb.
2 is a conventional lamp in which the region 25 in which the EC film 20 is formed is not formed. As can be seen from this figure, the black spots are scattered and the appearance is unsightly.

In the lamp shown in FIG. 5, the insulating film 21 and the phosphor film 22 are peeled off near the electrode 12 to form the EC film 2.
The lamp according to the present invention has a region 25 in which only 0 is formed. As can be seen from this figure, the occurrence of black spots is not observed, and it is confirmed that the appearance is improved.

The lamp of FIG. 6 is a lamp in which a region 60 in which only the insulating protective film 21 is cut away and the EC film 20 and the phosphor film 22 are left is provided in the vicinity of the electrode 12, and in this case, the EC film 20. And the area 6 where the phosphor coating 22 is left
0 is formed in a strip shape along the circumferential direction of the bulb. From this figure, it can be seen that even if the insulating protective film 21 is cut out, black spots are concentrated on the strip-shaped portion 60 and the appearance is deteriorated.

In FIGS. 7A and 7B, the insulating protective film 21 is formed at two places in the vicinity of the mark and on the back side thereof.
It is possible to examine the occurrence of blackening in the lamp provided with the regions 71 and 72 where the EC film 20 and the phosphor coating 22 are left only by cutting out only the EC film 20. Normally, the lamp has a product type mark formed on the outer surface of the bulb 10. In the case of a straight tube fluorescent lamp, the lamp outer surface is provided near the electrodes, and the manufacturer as shown in FIG. 7, FIG. 10 and FIG. A mark 30 (see FIG. 4 to FIG. 7) that indicates the type of trademark, size, output, etc.
Has been formed. The manufacturer recognizes that when the lamp is attached to the socket and used, the mark 30 faces downward, and the mark 30 is visible when looking up from the bottom, which is the correct usage pattern. However, even if the mark is used in an upright posture, there is no problem in lighting.

FIG. 7 shows an experiment of a lamp in which, in the vicinity of such a mark, only the insulating protective film 21 is cut out to form regions 71 and 72 where the EC film 20 and the phosphor film 22 are left. In FIG. 7A, only the insulating protective film 21 is cut out in the vicinity of the mark and the EC film 2 is formed.
0 and the phosphor film 22 has a laminated region 71 formed therein. As shown in FIG. 7A, even if the area 71 where the EC film 20 and the phosphor coating 22 are left is provided in the vicinity of the mark, black spots are concentrated on this area and the appearance is deteriorated. On the other hand, FIG. 7B shows a region 72 of the EC film 20 and the phosphor film 22 formed by cutting out only the insulating protective film 21 formed on the surface opposite to the surface on which the mark is provided. However, when the area 72 where the EC film 20 and the phosphor coating 22 are left is provided on the back surface side of the mark, the generation of black spots is small. It is considered that this is because the temperature rises in the region 72 located on the upper side due to the convection in the bulb during lighting, the insulation resistance of the phosphor coating 22 becomes low, and the slight discharge is hard to occur. The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention.

That is, in the above embodiment, the EC film 20
The region 25 formed with only the electrode is formed slightly closer to the discharge center than the electrode 12. However, in the case of the electrode structure without the shield ring 14, as shown in FIG. 8, the coil axis of the firanmet 12 is extended. A region 25 where only the EC film is formed may be provided on the line.

Further, as shown in FIG. 9, the area 25 where only the EC film 20 is formed is replaced with the quality indication mark 3 in the lamp.
It may be formed on the surface opposite to the surface on which 0 is formed, that is, on the back surface side. That is, the insulating protection film 21 as in the embodiment of FIG.
In a lamp having a region 25 in which only the EC film 20 is formed by peeling off the phosphor film 22, the blackening of the EC can be prevented and the luminous flux maintenance factor can be improved, but it is exposed in the discharge space. Mercury oxide H on the EC film 20 of
At the end of life due to the adhesion of gO, etc., blackening may occur. Therefore, if the area 25 in which only the EC film 20 is formed as shown in FIG. 9 is formed on the surface of the lamp opposite to the quality display mark 30, the quality display mark 30 is usually directed downward and can be seen from below. Therefore, even if blackening occurs in the region 25 in which only the EC film 20 is formed, it cannot be seen from the bottom, so that the appearance is prevented from being spoiled.

On the contrary, in the vicinity of the quality display mark 30, the quality display mark 3 formed of black or brown paint is used.
The light is blocked by 0, and the luminous flux is slightly reduced. Therefore, as shown in FIG. 10, the valve 1 is placed so as to overlap the area where the quality indicating mark 30 is formed.
If the region 25 in which only the EC film 20 is formed is formed on the inner surface side of 0, even if the region 25 in which only the EC film 20 is formed is blackened, this becomes inconspicuous and the appearance is not significantly impaired.

The EC film of the present invention is not limited to being formed of tin oxide, but may be tin oxide mixed with indium oxide or antimony-doped tin oxide. Also, the phosphor coating is not limited to the phosphor of the embodiment, and can be applied to other phosphors.
Furthermore, the shape of the lamp is not limited to the straight tube shape, but a ring shape, a U shape,
It may be a W-shaped fluorescent lamp.

[0034]

As described above, according to the present invention, since the EC film in the vicinity of the electrode is exposed on the inner surface of the bulb, the insulation resistance is small and electrons are easily conducted, so that the bulb wall resistance of the bulb is lowered. Therefore, starting the lamp becomes easier.
In addition, since the insulation resistance is kept high in the area where the EC film is not exposed, not only is the occurrence of minute discharge prevented, but the EC film is exposed even if the amount of charge accumulated in the phosphor film increases. The electric charge escapes to the EC film through the area indicated by, and the potential difference between the mercury Hg adhering to the phosphor film and the EC film is reduced, so that the occurrence of micro-discharge is prevented, and the phosphor film or It is possible to prevent spots from being formed on the EC film.

[Brief description of drawings]

FIG. 1 is a perspective view of a straight tube type rapid start type fluorescent lamp showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an end portion of the embodiment.

FIG. 3 is a schematic diagram for explaining the operation of the embodiment.

FIG. 4 is a perspective view showing how blackening occurs in the case of a conventional lamp.

FIG. 5 is a perspective view showing how blackening occurs in the lamp of the example of the present invention.

FIG. 6 is a perspective view showing a blackened state which occurs in a lamp of another example.

FIG. 7 is a perspective view showing a blackened state occurring in another lamp, FIG. 7A is an example near a display mark, and FIG.
The figure shows an example of the surface opposite to the display mark.

FIG. 8 is a perspective view of an end portion showing a second embodiment of the present invention.

FIG. 9 is a perspective view of an end portion showing a third embodiment of the present invention.

FIG. 10 is a perspective view of an end portion showing a fourth embodiment of the present invention.

[Explanation of symbols]

10 ... Bulb, 12 ... Electrode, 20 ... Transparent conductive film (E
C film), 21 ... Insulating protective film, 22 ... Fluorescent film, 25
... EC film only area, 30 ... Variety display mark.

Claims (5)

[Claims] 1. A transparent conductive film is formed on the inner surface of a glass bulb having electrodes sealed at its ends, and a protective film made of a transparent metal oxide is provided on the inner surface of the conductive film. In a rapid start fluorescent lamp in which a phosphor film is formed on the inner surface of the protective film and mercury is enclosed in the bulb, the protective film of the metal oxide and the phosphor described above are formed on the inner surface of the bulb located near the electrode. A rapid-start type fluorescent lamp characterized in that a transparent conductive film only is formed without forming a film. 2. The rapid start type fluorescent lamp according to claim 1, wherein the portion where the protective film of the metal oxide and the phosphor coating are not formed is provided on an extension line of the filament axis. 3. The rapid device according to claim 1, wherein the portion where the protective film of the metal oxide and the phosphor film are not formed is formed on the back surface opposite to the product type mark formed on the bulb. Start type fluorescent lamp. 4. The rapid start type fluorescent lamp according to claim 1, wherein the portion where the metal oxide protective film and the phosphor coating are not formed is formed at the position of the type indicating mark formed on the bulb. Light lamp. 5. The area where the metal oxide protective film and the phosphor film are not formed has an area of 25 mm ^2. The rapid start fluorescent lamp according to any one of claims 1 and 4, characterized by the above.