JPH1040861A - Fluorescent lamp - Google Patents

Abstract

(57) [Problem] To provide a fluorescent lamp with less blackening, in which the consumption of the emitter at the time of starting is small and the blinking life is improved. SOLUTION: The filament 5 is a triple coil,
ZrO ₂ which is a thermoelectron suppressing substance is added to the filament 5 in an amount of 0 to
A 1% by weight emitter is filled, and a shield ring 6 is provided around the filament 5 to prevent blackening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp, and more particularly, to a fluorescent lamp adapted to quality improvement such as improvement of blinking life and start-up performance.

[0002]

2. Description of the Related Art Research on the electrodes of a starter-type fluorescent lamp has been carried out for a long time, and many research results have been reported, and these technologies have been applied to products. BaO, CaO,
Oxides containing SrO as a main component have been used for a long time because of their good electron emission performance.

[0003] It is important for the electrodes of a fluorescent lamp to have as good a thermionic emission performance as possible in order to facilitate the start of discharge and repeated discharge during lighting, but at the same time, an emitter with excellent thermionic emission. In this method, a large amount of thermal evaporation occurs, and a part of the emitter scattered during the operation of the lamp adheres to the inner wall of the bulb of the lamp, causing an early blackening phenomenon. As a means for improving the blackening phenomenon, as proposed in Japanese Patent Publication No. 28-2118, a method in which an oxide having a high heat-resistant temperature including ZrO ₂ is mixed into the emitter by several wt% is adopted.

On the other hand, a double coil is generally used in a starter type fluorescent lamp for a filament, but a triple coil in which a filament temperature rises quickly is used in a rapid start type fluorescent lamp because of an immediate start method. I have. In order to prevent blackening, a shield ring is employed around the filament as disclosed in JP-A-5-290812. In any case, an emitter in which a heat-resistant oxide such as ZrO ₂ is mixed at several wt% is employed.

[0005]

The lamp current used for general lighting to which the above-mentioned prior art is applied is 10 or less.
The life of a starter type fluorescent lamp of 0 mA or more is obtained from several thousand hours to 12,000 hours. However, there is a problem in that the blinking life (lifetime when turning on and off repeatedly) is short.

The relationship between the flashing cycle of the fluorescent lamp and the life is described on page 24 of the Lighting Classroom 68 (September 1990, published by The Illuminating Engineering Institute / Lighting Promotion Association). Except for special cases, the life of the fluorescent lamp is such that the emitter filled in the filament is consumed (scattered), so that the discharge cannot be sustained and the lamp is not lit.

[0007] Sputtering of the emitter includes ion sputtering and thermal evaporation. These two emitter depletion mechanisms occur in the same way during the lamp start-up and during the ignition process, and in both processes the emitter depletion is caused by ion bombardment sputtering rather than thermal evaporation. Emitter scatter is much larger. Particularly at the start-up, since the temperature of the filament is low, sputtering by ion bombardment is large, and scattering of the emitter is large. Therefore, there is a problem in that the higher the frequency of blinking that repeats starting and lighting, the greater the scattering of the emitter, and the higher the frequency of blinking, the shorter the life. In addition, there is a problem in that the blackening phenomenon that occurs when the emitter scattered during lamp operation adheres to the inner wall of the lamp cannot be removed.

As a means of extending the blinking life, there is a method of increasing the amount of emitter. However, in the case of a double coil, since the emitter is filled in a primary coil wound with one tungsten wire, the holding power of the emitter is reduced. There is a problem that the amount of the emitter is weak and cannot exceed a certain range.
Also, ZrO ₂ has a problem in that it suppresses thermionic emission performance.

It is an object of the present invention to provide a fluorescent lamp having an improved blinking life. Another object of the present invention is to provide a fluorescent lamp with less blackening.

[0010]

In order to achieve the above object, according to the present invention, the heat-resistant oxide ZrO ₂ in the emitter is reduced from 0 to 0.
The fluorescent lamp is characterized in that it is 1 wt% and a shield ring is provided around the filament. Further, a triple coil may be used as the filament. The blackening phenomenon caused by reducing the heat-resistant oxide ZrO ₂ in the emitter can be prevented by a shield ring provided around the filament.

Since the heat-resistant oxide ZrO ₂ in the emitter suppresses thermionic emission performance, the less the amount of ZrO ₂ , the more thermionic emission performance is improved. In particular, the improvement of thermionic emission performance becomes remarkable at 1 wt% or less. Therefore, by setting ZrO ₂ to 1 wt% or less, the ratio of ion bombardment becomes small and the scattering of the emitter is reduced. In particular, the effect is large at the time of starting when the filament temperature is low, and the filament is more remarkable in a triple coil having a large temperature rise.

[0012] Further, this has a secondary effect of lowering the starting voltage, and it has been recognized that the starting performance at low temperatures is improved as compared with the conventional case.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are cross-sectional views showing an end of a straight tube starter type fluorescent lamp according to an embodiment. The lamp current is 100 mA or more, and the inner diameter of the glass bulb 1 is 10 mm or more. The straight tube starter type fluorescent lamp includes a coating of a phosphor 2 on an inner surface of a glass bulb 1 and a stem 4 having electrode portions at both ends. After exhausting the air inside, an appropriate amount of mercury and a rare gas are sealed. A base 3 having two pins is attached to both ends of the sealed valve.
In the electrode part, the filament 5 is connected to the two lead wires of the stem 4.
Is spanned. A shield ring 6 for preventing blackening is provided around the filament 5.

FIG. 3 is an enlarged view of the filament portion of the electrode portion. The filament 5 is a triple coil 5a filled with an emitter 5b. The triple coil is obtained by further winding a primary coil in which a sub wire tungsten having a diameter smaller than the main wire is wound on a main wire tungsten to form a secondary coil, and further winding the secondary coil to form a tertiary coil.
However, FIG. 3 shows only the subline tungsten in a simplified manner.

With such a configuration, in a straight tube starter type 40 watt fluorescent lamp, ZrO ₂ in the emitter 5b is used.
The mixing ratio is set to 0 to 5 wt%, and the blinking cycle (1 minute lighting-
(2 minutes off) to evaluate the blinking life. The main component of the emitter 5b has a (BaO: CaO: SrO) ratio of (47: 1).
8:34) wt%, and the filling amount of the emitter is 4.3 to
4.5 mg.

FIG. 4 is a diagram showing the relationship between the ZrO ₂ mixing ratio and the obtained blinking life. The flashing life of a lamp using an emitter having a ZrO ₂ contamination rate of 0 wt% is shown as 100%. The refractory oxide ZrO ₂ in the emitter by a 0 to 1 wt%, it was possible to improve the flashing life.
The effect was less pronounced when the same blinking life was attempted with a double coil (FIG. 4). Further, the blackening phenomenon did not occur until near the life due to the shield ring.

As a result of confirming the starting performance of the above lamp, the lamp having ZrO ₂ of 0 to 1% by weight has a ZrO ₂ of 2 wt%.
It was also found that the starting voltage was about 3-5 V lower than that of a -5 wt% lamp. Thus, the starting performance can be improved even when the diameter of the glass bulb is reduced.

In the case of a fluorescent lamp with a very small current, such as a backlight having a bulb inner diameter of 10 mm or less and a lamp current of 50 mA or less, the effect on the blinking life is not so much obtained. Although the cause is not clear, it is considered that thermionic emissivity is improved, the cathode voltage is reduced by the electron emission, and the emitter is easily consumed.

[0019]

According to the present invention, the blinking life and the starting performance can be improved, the blackening can be prevented, and the quality of the fluorescent lamp can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an end of a starter-type fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is another sectional view showing an end of the starter-type fluorescent lamp according to the embodiment of the present invention.

FIG. 3 is an enlarged view of a filament portion.

FIG. 4 is a graph showing a relationship between a ZrO ₂ mixing ratio and a blinking life.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass bulb, 2 ... Phosphor, 3 ... Base, 4 ... Stem, 5 ... Filament, 5a ... Triple coil, 5b ... Emitter, 6 ... Shield ring.

Claims (6)

[Claims] 1. A glass bulb having an inner surface coated with a phosphor, a filament, and a filament filled in the filament.
A fluorescent lamp comprising: an emitter containing aO, CaO, and SrO; a shield ring provided around the filament; and ZrO ₂ added to the emitter by 1 wt% or less. 2. The filament further comprises a secondary coil formed by further winding a primary coil in which a sub-line tungsten having a diameter smaller than that of the main line tungsten is wound around a main line tungsten,
The fluorescent lamp according to claim 1, wherein the secondary coil is a triple coil formed by further winding the secondary coil. 3. A lamp current flowing through said filament is 100 mA or more, and said glass bulb has an inner diameter of 10 mA.
The fluorescent lamp according to claim 2, wherein the diameter is equal to or more than mm. 4. A lamp current flowing through the filament is 50 mA or more, and an inner diameter of the glass bulb is 10 m.
3. The fluorescent lamp according to claim 2, wherein the distance is at least m. 5. A glass bulb having an inner surface coated with a phosphor, a filament, and a filament filled in the filament,
a primary coil comprising: an emitter containing aO, CaO, and SrO; and a shield ring provided around the filament, wherein the filament is formed by winding a main wire tungsten with a sub wire tungsten thinner than the diameter of the main wire tungsten. Are further wound into a secondary coil, and the secondary coil is further wound into a tertiary coil to form a triple coil. 6. A lamp current flowing through said filament is 100 mA or more, and said glass bulb has an inner diameter of 10 mA.
The fluorescent lamp according to claim 5, wherein the diameter is not less than mm.