JP2000195465A - Fluorescent lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp capable of not only showing an excellent luminous flux maintenance factor but also building up the luminous flux at the initial stage of lighting, by mercury adhered to and remained on the phosphor layer surface during light-out time and separated from the phosphor layer surface at the time of subsequent lighting, and to provide a lighting system capable of obtaining stable luminescence. SOLUTION: This fluorescent lamp is equipped with a light transmitting glass tube 4 filled with filler gas containing amalgam exhibiting vapor pressure of mercury close to pure mercury and noble gas, a fluorescent layer 5 containing a phosphor particle 5a provided on the inner wall surface of the light transmitting tube 4, and, a means of maintaining positive column discharge in the filler gas, and a negatively charged metal oxide or a non-organic compound 5b is adhered to the surface of the phosphor particle 5a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorescent lamp,
More specifically, the present invention relates to an improvement of a fluorescent lamp in which amalgam is enclosed as a mercury vapor source.

[0002]

2. Description of the Related Art Fluorescent lamps are used in a wide range of fields, such as general lighting, light sources for office automation equipment, and backlights for liquid crystal displays, because they can efficiently convert supplied electric power into visible light radiation. . In recent years, compact and high performance light sources have been promoted in response to miniaturization of equipment to be used.

[0003] Such a light source is used for preventing and improving a reduction in the luminous flux maintenance rate of a fluorescent lamp.
Prevention and improvement of the phenomenon of blackening at an early stage, and improvement of the light rise characteristics immediately after lighting are required. In response to these improvements and demands, the charge tendency is more negative than that of metal oxides with a metal ion electronegativity of 7.0, and the electronegativity of metal ions is 1
It is known that phosphor particles on the more positive side than the 1.8 metal oxide are used for forming a fluorescent layer on the inner wall surface of a fluorescent lamp (Japanese Patent Application Laid-Open No. 5-325901).

On the other hand, for appropriate control of the mercury vapor pressure corresponding to the high load of the fluorescent lamp, or as an environmental measure,
It is also known to use so-called amalgam (mercury amalgam) as a method for quantitatively enclosing mercury. That is,
(a) Amalgam is sealed at one end of the luminescent glass tube to control the mercury vapor pressure inside the luminescent glass tube, and auxiliary amalgam is sealed and installed near the electrodes to remove the required mercury immediately after lighting in the luminescent glass tube. To improve the starting and rising characteristics, and (b) mixing amalgam in the fluorescent layer as a measure for improving the above (a) has been proposed (Japanese Patent Application Laid-Open No. 8-31374).

[0005]

However, even in the case of the configuration (a) in which the auxiliary amalgam is enclosed and installed, it takes time for the mercury released from the auxiliary amalgam to diffuse into the light emitting glass tube after lighting. However, there is a problem that the luminous flux rising characteristic is inferior to that of a normal fluorescent lamp.
On the other hand, adopt a configuration in which amalgam is mixed in the fluorescent layer (b)
In case (1), although the improvement is recognized by the selection of amalgam, there is still a problem. In other words, in consideration of low-temperature startability, mercury amalgam having a vapor pressure close to that of pure mercury (presented) is enclosed and arranged in the exhaust tube, and when auxiliary amalgam is used in combination with amalgam having a low mercury vapor pressure, the luminous flux is reduced. The rise characteristics can be improved, but conversely, the low-temperature startability is reduced. In particular, since the tube wall temperature tends to rise more rapidly as the load of the fluorescent lamp increases, mercury is adsorbed to the fluorescent layer and the light flux tends to rise slowly.

In the formation of the fluorescent layer on the inner wall surface of the fluorescent lamp, the charge tendency is on the more negative side than the metal oxide having an electronegativity of 7.0 of the metal ion, and the charge tendency is lower than that of the metal oxide having an electronegativity of 11.8 of the metal ion. In the case of the configuration using the phosphor particles on the positive side, the mercury vaporized at the time of turning off the light is drawn to the amalgam. However, since the surface of the phosphor and mercury are charged to the same polarity, adhesion of mercury to the surface of the phosphor
As a result, there is a tendency that the luminous flux rising characteristic in the initial stage of lighting after the fluorescent lamp has been turned off and stored for a long period of time is significantly reduced, and practicality is impaired.

The present invention has been made in view of the above circumstances, and exhibits not only an excellent luminous flux maintenance factor, but also mercury adheres to and remains on the phosphor layer surface during the light-out period, and when the lamp is turned on thereafter, It is another object of the present invention to provide a fluorescent lamp in which mercury separates from the phosphor layer surface to easily raise the luminous flux at the initial stage of lighting, and to provide a lighting device capable of obtaining stable illumination.

[0008]

According to the first aspect of the present invention, there is provided a light-transmitting glass tube filled with a filling gas containing amalgam and a rare gas exhibiting a mercury vapor pressure close to that of pure mercury; In a fluorescent lamp comprising: a fluorescent layer including phosphor particles provided on a wall surface; and means for maintaining a positive column discharge in the sealing gas, the surface of the phosphor particles forming the fluorescent layer is negatively charged. And a metal oxide or an inorganic compound.

A second aspect of the present invention is a light-transmitting glass tube filled with a filling gas containing amalgam and a rare gas having a mercury vapor pressure close to that of pure mercury; and a light-resistant glass provided on the inner wall surface of the light-transmitting glass tube. A fluorescent layer comprising: a coloring protective layer; a fluorescent layer including phosphor particles provided on the surface of the coloring-resistant protective layer; and means for maintaining a positive column discharge in the sealed gas. A fluorescent lamp characterized in that a negatively charged metal oxide or inorganic compound is attached to the surface of the phosphor particles forming a layer.

According to a third aspect of the present invention, in the fluorescent lamp according to the first or second aspect, the negatively charged metal oxide or inorganic compound adhering to the surface of the phosphor particles comprises silica, boric acid, and titanium oxide. It is characterized by being at least one of them.

According to a fourth aspect of the present invention, in the fluorescent lamp according to any one of the first to third aspects, the light-transmitting glass tube is a curved tube having at least one U-shaped bent portion. It is characterized by the following.

According to a fifth aspect of the present invention, there is provided an illuminating apparatus comprising: a fluorescent lamp luminaire; and the fluorescent lamp according to any one of the first to fourth aspects mounted on the fluorescent lamp luminaire. It is.

In the first to fourth aspects of the present invention, the light-transmitting glass tube is formed of a glass material used for a fluorescent lamp (low-pressure mercury vapor discharge lamp), and is a direct-type, annular type. , U-shape, W-shape and the like, and have a generally known configuration together with the filling gas. On the other hand, amalgam enclosed in a light-transmissive glass tube exhibits a mercury vapor pressure close to that of pure mercury.
Mercury (Bi-Sn-Hg) and the like. Where amalgam is
When the fluorescent lamp is initially turned on (at the time of manufacture), the fluorescent lamp is enclosed and arranged in a narrow tube for exhaustion of a light-transmissive glass tube, and a form in which a so-called auxiliary amalgam is omitted is adopted. In other words, immediately after manufacturing, and before lighting, amalgam exhibiting a mercury vapor pressure close to that of pure mercury is arranged in a region other than the discharge space of the fluorescent lamp, and assumes a state not interposed in a so-called discharge space (discharge region). ing.

In the first to fourth aspects of the present invention, the negatively charged metal oxide or inorganic compound attached to the surface of the phosphor particles contained in the phosphor layer has a negative charge based on the mercury oxide. Is caused. That is, when two types of substances come into contact, an equal amount of charge is generated on the surface of each substance, and a substance generating a positive charge has a positive charge tendency, and a substance generating a negative charge has a negative charge tendency. It is said to have Furthermore, if mentioned, as a result, a required amount of a negatively charged metal oxide (about 0.01 to 5% by weight with respect to the phosphor particles) is deposited so that the fluorescent layer exhibits a negative charge tendency. It is a thing.

The measurement and evaluation of the charge or the charge tendency can be performed by, for example, a blow-off powder charge measuring device using a Farrer gauge. In the relative order of the charging tendency, each substance is classified into a positively charged metal oxide or a negatively charged metal oxide. Examples of such negatively charged metal oxides include silica, boric acid, titanium oxide, and zinc oxide. In particular, at least one kind selected from the group consisting of silica, boric acid, and titanium oxide Metal oxides (including mixtures) are preferred.

In the first to fourth aspects of the present invention, the means (discharge means) for maintaining the positive column discharge in the gas filled in the light transmitting glass tube generally forms a positive column discharge path. Although a pair of electrodes are sealed opposite to both ends of the light-transmitting glass tube, a structure in which at least one electrode is arranged outside the light-transmitting glass tube may be used.

Furthermore, if necessary, the inner wall surface of the light-transmitting glass tube is prevented from coloring the light-transmitting glass tube due to the reaction between the glass and mercury due to ultraviolet rays, preventing a reduction in the luminous flux maintenance rate, and preventing a reduction in the strength of the light-transmitting glass tube. For this purpose, a coloring-resistant protective layer may be used as a base of the fluorescent layer, and a protective layer having a thickness of about 0.05 to 10 μm may be interposed. Here, the protective layer is preferably, for example, an aluminum oxide layer also serving as an ultraviolet reflective layer.

According to a fifth aspect of the present invention, the luminaire corresponds to the fluorescent lamp of the first to fourth aspects, and is generally used in accordance with the standard, shape, size, application, and the like of the fluorescent lamp. You can choose from the lighting fixtures that are available.

In the first to fourth aspects of the present invention, the negatively charged metal oxide is attached to the surface of the phosphor particles forming the fluorescent layer, with respect to the mercury attracted to the amalgam and charged to the positive side. Therefore, mercury is reliably and easily retained on the surface of the fluorescent layer during the light-out period, and at the time of lighting, the mercury is easily separated from the surface of the fluorescent layer to exhibit a good luminous flux rising characteristic. This effect is more effective for a high-load fluorescent lamp in which the tube wall temperature tends to rise rapidly. That is,
It is possible to provide a fluorescent lamp in which the load of the fluorescent lamp is increased and the luminous flux reduction rate during lighting and prevention of early blackening are improved.

According to the fifth aspect of the present invention, since the fluorescent lamp is used as a light source, it is easy to handle and high quality indoor lighting.
A light source for a backlight can be provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS.

Embodiment 1 FIG. 1 is a partially cutaway sectional view showing a main part of a straight tube type fluorescent lamp according to this embodiment, wherein 1 is a straight tube type light transmitting glass tube, and 2 is a straight tube type light transmissive glass tube. The fluorescent layers 3a and 3b provided on the inner wall surface of the tube-shaped light-transmitting glass tube 1 are bases. A rare gas is sealed in the straight tube-type light transmissive glass tube 1, and a pair of electrodes (not shown) are electrically connected to the bases 3a and 3b and sealed at both ends. Further, Bi-Sn-Hg amalgam is also enclosed in the exhaust pipe at one end.

Here, the light transmitting glass tube 1 has a tube diameter of 16 mm,
It is a soda-lime glass tube with a length of 540mm. The fluorescent layer is made of three-wavelength luminescent phosphor particles, and 2% by weight of negatively charged silica (trade name.) With respect to the phosphor particles.
(Snowtex, manufactured by Nissan Chemical Industries, Ltd.), an aqueous binder and a γ-alumina binder. As the three-wavelength light emitting phosphor, for example, a blue phosphor (SrCa
_{Ba) 5 (PO 4) 3} Cl: Eu or _{BaMg 2 Al 16 O 27: Eu} , M
n, LaPO ₄ : Ce, Tb as a green phosphor, and Y ₂ O ₃ : Eu as a red phosphor, but are not limited thereto.

The above-mentioned fluorescent lamp exhibited not only a good luminous flux rising characteristic at the initial lighting, but also almost no change in the luminous flux rising characteristic, for example, two months after the light was turned off. The luminous flux maintenance ratio and the prevention of early blackening were also good.

Embodiment 2 FIG. 2 is a partially cutaway sectional view showing a main part of a light bulb-type fluorescent lamp according to this embodiment. In FIG. 2, reference numeral 4 denotes a light-transmitting glass tube formed by connecting three glass tubes bent in a U-shape to form one discharge path, and reference numeral 5 denotes an inner wall surface of the W-shaped light-transmitting glass tube 4. The provided fluorescent layer 6 is a cover provided with a base 7 at one end and a holder 8 for fixing and mounting the curved light transmissive glass tube 4 at the other end.
Reference numeral 9 denotes a light-transmitting glove which is attached to the other end of the cover 6 by engagement or the like and seals the bent light-transmitting glass tube 4, and reference numeral 10 denotes a space formed by the holder 8 and the cover 6. It is a lighting circuit mounted on.

The bent light-transmitting glass tube 4
A rare gas is sealed therein, and a pair of electrodes are electrically connected and sealed to the base 7 at both end sides thereof. Further, a predetermined amount of gas is contained in an exhaust thin tube 4a arranged at the end side. Bi-S
Contains n-Hg amalgam.

Here, the bent light transmitting glass tube 4
Is a lead glass tube having a diameter of 10 mm and a length of 120 mm, which is bent into a U-shape and joined together so as to form a triangular cross section. On the inner wall surface, FIG. As schematically shown in the portion, an aluminum oxide film 4b having a thickness of about 1 μm is formed. This aluminum oxide film 4b
Glass tube 4 by reaction between mercury and glass by ultraviolet rays
Function as a protective film for preventing coloring, preventing a reduction in the luminous flux maintenance rate, and preventing a decrease in the strength of the glass tube 4.

The fluorescent layer 5 is made of three-wavelength luminescent phosphor particles 5a and a negatively charged silica (trade name: Snowtex, manufactured by Nissan Chemical Co., Ltd.) at a weight ratio of% to the phosphor particles 5a. ) 5b, aqueous binder and γ-alumina binder
It is formed by applying and baking a phosphor mixture obtained by mixing and preparing 5c.

The above-mentioned fluorescent lamp exhibited not only good luminous flux rising characteristics at the initial lighting but also almost no change in luminous flux rising characteristics, for example, two months after the light was turned off. That is, after the light is turned off, the mercury that has contributed to the discharge / emission is easily captured by the negatively charged silica 2b of the fluorescent layer 5 that has also contributed to the light emission, and remains in the glass tube 4 forming the discharge space. In addition, the light beam rises quickly even during the subsequent lighting.

A curve A in FIG. 4 shows an example of the relationship between the staying time of the fluorescent lamp immediately after turning off the light and the amount of mercury remaining in the discharge space. In addition,
For reference, in the case of a fluorescent lamp having the above-mentioned configuration and the same conditions except that the silica 2b was not mixed into the fluorescent layer 2, the result was as shown by a curve a. In other words, immediately after the lamp was turned off, the amount of mercury was 0.5 mg for all the fluorescent lamps. However, in the case of the fluorescent lamps according to the examples, almost no change was observed even after two months of staying off due to the mercury trapping effect of the fluorescent layer 2. unacceptable. On the other hand, in the case of the fluorescent lamp according to the reference example, the mercury is attracted to the amalgam, and is reduced to 0.01 mg after two months of the staying out.

The amount of mercury in the glass tube 4 caused by the above-mentioned staying off depends on the rise of the luminous flux at the time of starting the lighting, and as shown in FIG. 5, in the case of the fluorescent lamp according to the embodiment, as shown in FIG. At both the time point (curve B) and the one-month stay-off time (curve B ′), the time (rise) until the luminous flux reached 80% was 30 seconds or less. On the other hand, in the case of the fluorescent lamp according to the reference example, the time (rise) until the luminous flux reaches 80% at the time of turning-off stay 0 (curve b) slightly exceeds 30 seconds, and at the time of one month of staying off. (Curve b ') is 2
More than a minute.

Such an operation and effect is effective for a fluorescent lamp having a diameter of 20 mm or less, which has a large effect of releasing mercury from the fluorescent layer 5 and has a large tube wall load, when the arc tube temperature rises immediately at the start of lighting.

In each of the above embodiments, similar results can be obtained by using other negatively charged metal oxides such as boric acid and titanium oxide instead of silica.
Even if γ-alumina (binder) is omitted, a negatively charged metal oxide tends to be used alternately.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the material of the light-transmitting glass tube,
The shape can be appropriately selected according to the application, such as the type of phosphor and the specifications of the fluorescent lamp.

[0035]

According to the first to fourth aspects of the present invention, mercury in the fluorescent lamp is easily retained on the surface of the fluorescent layer during the turn-off period, and is easily separated from the surface of the fluorescent layer at the start of lighting. , Good luminous flux rising characteristics. And
This effect is more effective for a high-load fluorescent lamp in which the tube wall temperature tends to rise rapidly. Therefore, it is possible to provide a fluorescent lamp in which the load of the fluorescent lamp is increased, the luminous flux reduction rate during lighting, the early blackening prevention and the luminous flux rising characteristics are improved.

According to the fifth aspect of the present invention, since the fluorescent lamp is used as a light source, it is easy to handle and high quality indoor lighting.
A light source for a backlight is provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway cross-sectional view showing a configuration of a main part of a fluorescent lamp according to a first embodiment.

FIG. 2 is a partially cutaway sectional view showing a configuration of a main part of a fluorescent lamp according to a second embodiment.

FIG. 3 is an enlarged cross-sectional view schematically showing a part of FIG. 2;

FIG. 4 is a characteristic diagram showing a comparative example of a change in the amount of mercury in the fluorescent lamp during the non-lighting stay period for the fluorescent lamps according to the example and the reference example.

FIG. 5 is a characteristic diagram showing a comparison between fluorescent lamp luminous flux rising characteristics examples according to an example and a reference example.

[Explanation of symbols]

 1,4 ... Transparent glass tube 2,5 ... Fluorescent layer 3a, 3b, 7 ... Base 4a ... Exhaust tube 4b ... Alumina layer 5a ... Phosphor particles 5b ... Silica 5c ... Alumina Binder 8 Holder 9 Globe 10 Lighting circuit

Claims (5)

[Claims] 1. A light-transmitting glass tube filled with a filling gas containing amalgam and a rare gas having a mercury vapor pressure close to that of pure mercury; and a fluorescent light containing phosphor particles provided on an inner wall surface of the light-transmitting glass tube. A fluorescent lamp comprising: a layer; means for maintaining a positive column discharge in the sealed gas, wherein a negatively charged metal oxide or an inorganic compound is attached to the surface of the phosphor particles forming the fluorescent layer. A fluorescent lamp. 2. A light-transmitting glass tube filled with a filling gas containing amalgam and a rare gas having a mercury vapor pressure close to that of pure mercury; and a coloring-resistant protective layer provided on the inner wall surface of the light-transmitting glass tube. A fluorescent layer comprising phosphor particles provided on the surface of the coloring-resistant protective layer; and a means for maintaining a positive column discharge in the sealed gas, wherein a fluorescent light forming the fluorescent layer is provided. A fluorescent lamp characterized in that a negatively charged metal oxide or inorganic compound is attached to the surface of body particles. 3. The method according to claim 1, wherein the negatively charged metal oxide or inorganic compound attached to the surface of the phosphor particles is at least one of silica, boric acid and titanium oxide. 2. The fluorescent lamp according to 2. 4. The fluorescent lamp according to claim 1, wherein the light-transmitting glass tube has a curved tube shape having at least one U-shaped bent portion. 5. A lighting apparatus comprising: a lighting device for a fluorescent lamp; and the fluorescent lamp according to claim 1 mounted on the lighting device for a fluorescent lamp.