JP2001052648A - Fluorescent lamp and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp capable of suppressing a drop of light flux originating from penetration of a protection film material solution into a phosphor layer. SOLUTION: A phosphor layer 3 is formed on the inner surface of a glass tube 2, and a yttrium oxide (Y2O3) film 4a being metal oxide film as protection film is applied to the surface of the phosphor layer 3 without penetrating into its inside. A solution is prepared by mixing a binder having a very high viscosity such as hydroxy-propyl cellulose diluted with water with a trimethyl yttrium solution or carbonyl yttrium solution, and the obtained solution is atomized, blown into the glass tube from a nozzle positioned close to one-end opening of the glass tube 2, and applied to the phosphor layer 3 so that the Y2O3 film 4a is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorescent lamp and a method for manufacturing the same.

[0002]

2. Description of the Related Art During the operation of a fluorescent lamp, mercury is ionized and easily reacts with other substances. Therefore, the residual gas, the phosphor, oxygen in the glass tube or sodium from the glass tube reacts with ionized mercury to form a mercury compound such as mercury oxide or amalgam. Since this mercury compound does not emit ultraviolet light, the fluorescent lamp does not emit light when all mercury is converted into a compound. In a conventional fluorescent lamp, mercury far exceeding the amount of mercury consumed as a compound is sealed in a glass tube to prevent the mercury from being consumed and obtain a rated life.
However, encapsulating a large amount of mercury, which is a harmful substance, is a very important issue in environmental protection.

Conventionally, it has been possible to prevent a reaction between a phosphor and mercury by forming a protective film made of a metal oxide on the phosphor layer to substantially prevent contact between the phosphor and mercury. It is known that a diethoxymagnesium solution (protective film material solution) prepared by dissolving metallic magnesium in methoxyethanol is coated on the phosphor layer, dried, evaporated to volatilize ethanol, and then fired. A protective film made of magnesium oxide is formed.
No. 30788).

[0004]

However, when the viscosity of the protective film material solution is low, the phosphor layer is like sand and the liquid is easily penetrated. This penetrates into the gaps between the phosphor particles, and a protective film made of a metal oxide is formed in the phosphor layer. Since the metal oxide used for the protective film absorbs ultraviolet light or visible light, there is a problem in that the protective film formed in the phosphor layer reduces the luminous efficiency of the phosphor and causes the luminous flux of the fluorescent lamp to decrease. there were.

The present invention has been made to solve such problems, and provides a fluorescent lamp and a method of manufacturing the same, which can suppress a decrease in luminous flux due to penetration of a protective film material solution into a phosphor layer. The purpose is to do.

[0006]

A fluorescent lamp according to the present invention comprises:
A protective film is provided on a phosphor layer formed on the inner surface of a glass tube without penetrating into the phosphor layer. With this configuration, it is possible to prevent mercury ions from bonding with oxygen in the phosphor or sodium diffused from the glass tube below the phosphor layer. Since the protective film is only on the surface of the phosphor layer, absorption of ultraviolet rays can be reduced as much as possible, and the visible light emitted from the phosphor does not hinder the diffusion of the visible light from the lamp toward the glass. Can be suppressed from decreasing.

According to the method of manufacturing a fluorescent lamp of the present invention, a solution of a metal alkoxide or a metal carboxylate having a viscosity of 3 cp or more and 50 cp or less is atomized from one end opening of a glass tube having a phosphor layer formed on the inner surface. The solution is applied onto the phosphor layer by blowing.
According to this method, the solution of the metal alkoxide or the metal carboxylate can be deposited thinly only on the phosphor layer surface, and the permeation into the phosphor layer can be reduced.

Further, in the method of manufacturing a fluorescent lamp according to the present invention, an outlet having a first outlet and a second outlet formed outside the first outlet is provided at the opening of the glass tube. In the method, the solution is atomized and blown into the glass tube from the first outlet, and a gas containing no solution is blown into the glass tube from the second outlet. According to this method, the amount of the solution adhering in the vicinity of the end of the glass tube can be reduced by the gas supplied from the second outlet, so that the glass tube can be applied with a uniform thickness in the tube axis direction. .

Further, the method for manufacturing a fluorescent lamp according to the present invention comprises:
Instead of blowing the solution in a mist form from one end opening of the glass tube, insert a blow-out tube having a plurality of blow-out ports into the glass tube into the glass tube by spraying the solution from the plurality of blow-out ports. The solution is applied to the inner surface of the glass tube by blowing. With this method, the coating time can be reduced,
By controlling the amount of application from each outlet, a raw material solution having a uniform thickness can be applied.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, in a fluorescent lamp 1 according to one embodiment of the present invention, a phosphor layer 3 and a protective film 4 are formed on the inner surface of a glass tube 2, and caps 5 are provided at both ends of the glass tube 2. Have been. Mercury, argon, or the like is sealed in the discharge space inside the glass tube 2, and electrodes (not shown) are provided at both ends inside the glass tube 2. FIG. 1 is an enlarged view of the glass tube 2 and its inner surface. In this figure, an alumina protective layer 6 is provided between the glass tube 2 and the phosphor layer 3, but as shown in FIG. May not be provided.

As shown in FIG. 1, in the fluorescent lamp of the present embodiment, a yttrium oxide (Y ₂ O ₃ ) film 4a, which is a metal oxide film, is applied to the surface of the phosphor layer 3 as a protective film. _{The 2} O ₃ film 4 a functions to suppress the penetration of mercury atoms into the phosphor layer 3. As a result, the bonding between mercury and oxygen in the phosphor layer 3 and sodium in the glass tube 2 is suppressed, and mercury consumption can be reduced. The surface thickness of the Y ₂ O ₃ film 4a to the thickness of about 15μm of the phosphor layer 3 are 0.3μm or less, Y ₂ O ₃ film 4a is a phosphor layer 3
The surface of the phosphor layer 3 is covered without any gap according to the unevenness of the surface of the phosphor layer 3 without penetrating into the inside of the substrate. Where Y ₂
Surface thickness of O ₃ film 4a is the thickness of the Y ₂ O ₃ film 4a as viewed from the surface of the phosphor particles 7 constituting the phosphor layer 3. Further, Y ₂ O ₃ for film 4a is the effect of suppressing the intrusion of mercury atoms into the phosphor layer 3 during fades thin, Y ₂ O ₃
The surface thickness of the film 4a is preferably 0.1 μm or more.

The Y ₂ O ₃ film 4a is substantially transparent to ultraviolet light having a wavelength of 254 nm, has a sufficiently small surface thickness of 0.3 μm or less, and covers only the surface of the phosphor layer 3.
It rarely interferes with the UV light reaching the surface. Also,
Visible light emitted from the phosphor toward the glass side is hardly absorbed by the Y ₂ O ₃ film because there is almost no Y ₂ O ₃ film in its path, and thus a reduction in the luminous flux of the fluorescent lamp can be suppressed.

In the conventional fluorescent lamp, the protective film penetrates into the phosphor layer, and the protective film absorbs ultraviolet light and visible light, so that the initial light flux is reduced. For example,
The initial luminous flux of the conventional fluorescent lamp was reduced by 5 to 10% with respect to the initial luminous flux of the fluorescent lamp without the protective film. However, the fluorescent lamp of the present embodiment reduced the initial luminous flux by 3% or less. We were able to.

Next, a method of manufacturing the fluorescent lamp shown in FIG. 1, particularly a method of forming a protective film on the phosphor layer will be described with reference to the drawings.

As shown in FIG. 3A, a raw material solution serving as a raw material for the Y ₂ O ₃ film is supplied from a blowout port 9 located near one end opening of a glass tube 8 on which a phosphor layer is formed. The raw material solution is applied on the phosphor layer by atomizing and blowing into the glass tube 8. The glass tube 8 is installed substantially horizontally, and suction is performed using the suction tube 10 at the other end opening of the glass tube 8, and by controlling the blowing speed and the suction speed, the thickness at which the raw material solution is applied is reduced. The uniformity can be obtained in the tube axis direction of the glass tube 8. Further, by applying the raw material solution while rotating the glass tube 8 as shown by an arrow, the raw material solution can be applied to the glass tube 8 in a uniform thickness in the circumferential direction. As a result, the surface film thickness of the protective film becomes uniform, it is possible to form the protective film having the minimum necessary thickness, and it is possible to suppress a decrease in the initial light flux. Further, as shown in FIG. 3 (b), the raw material solution is sprayed in the form of a mist from the outlets 9 located close to the openings at both ends of the glass tube 8, respectively, in a shorter time than when blowing from one side. A raw material solution can be applied.

As a raw material solution, a trimethyl yttrium solution as a metal alkoxide or a carbonyl yttrium solution as a metal carboxylate is used. If the viscosity of the raw material solution is low, it penetrates into the phosphor layer, but if the viscosity is high, it hardly penetrates into the phosphor layer, so that it can be applied only to the surface of the phosphor layer and its vicinity. In the present embodiment,
Highly viscous hydroxypropylcellulose (HP
The viscosity of the raw material solution was adjusted by diluting a binder such as C) or polyethylene oxide (PEO) with water and mixing it with the raw material solution. Since these binders are completely burned in the phosphor baking step, the decrease in luminous flux can be suppressed without increasing the residual carbon that causes the decrease in luminous flux. By setting the viscosity of the raw material solution to 3 cp or more, coating could be performed only on the surface of the phosphor layer. Further, when the viscosity of the raw material solution exceeds 50 cp, it becomes difficult to atomize and blow the raw material solution.

In this embodiment, in order to form the protective film only on the surface of the phosphor layer and in the vicinity thereof, the viscosity of the raw material solution as the raw material of the protective film is set to 3 cp or more. In the case of such a highly viscous raw material solution, in a conventional method in which a glass tube is set so that the tube axis is in a vertical direction and the raw material solution is poured from an upper end opening of the glass tube, it takes a considerable time to apply the raw material solution. And the production efficiency deteriorates. Compared with the conventional method, the application method according to the present embodiment reduces the time required for application to about half, and can improve the manufacturing efficiency.

After drying by blowing hot air at 100 ° C. for 5 minutes into the glass tube 8 coated with the raw material solution serving as the raw material of the Y ₂ O ₃ film by the above-described method, the phosphor is heated at 550 ° C. Is fired to form a Y ₂ O ₃ film. Thereafter, the fluorescent lamp is completed by a normal manufacturing method. That is, the process is the same as the process of manufacturing a normal fluorescent lamp except for the step of applying the raw material solution. Next, another method for applying the raw material solution for the protective film on the phosphor layer will be described.

When the raw material solution for the protective film is sprayed from the outlet 9 having an inner diameter substantially the same as the inner diameter of the glass tube 8, as shown in FIG. The particles 11 tend to adhere, and the amount of the raw material solution applied increases at the end of the glass tube 8. Therefore, FIG.
As shown in the figure, the inner diameter of the inner outlet is smaller than the inner diameter of the glass tube 8, and using the outlet 12 having a double structure having the outer outlet around the inner outlet,
Spray the mist of the raw material solution from the inner outlet,
By blowing a gas containing no raw material solution from the outer blowing port as shown by 3, the raw material solution in the form of a mist near the end of the glass tube 8 is shielded by the gas and adhesion is suppressed. As a result, it is possible to apply the raw material solution having substantially the same thickness at the end and the center of the glass tube 8.

Instead of blowing the raw material solution from the end of the glass tube, as shown in FIG. 5A, the blowing tube 14 is inserted or pulled out from the opening of one end of the glass tube 8 at the tip of the blowing tube 14. The raw material solution can be sprayed from the outlet 15. According to this method, since a fixed amount of the raw material solution can be applied to each position on the inner surface of the glass tube 8, the thickness can be made uniform. FIG.
As shown in (b), the raw material solution may be sprayed while moving the glass tube 8 with the blowing tube 14 fixed. In this case, the outlet 15 at the tip of the outlet tube 14 is fixed and does not vibrate, so that the distance between the inner surface of the glass tube 8 and the outlet 15 can be kept constant. Can be applied. Further, as shown in FIG. 5C, the blowing solution 14 may be inserted from both ends of the glass tube 8 and the raw material solution may be blown from the blowing port 15. According to this method, the raw material solution can be applied in a short time.

A diffuser plate as shown in FIG.
Can be uniformly scattered, so that the raw material solution can be more uniformly applied to the inner surface of the glass tube. Examples of the diffusion plate include a flat diffusion plate 16 shown in FIG.
A conical diffusion plate 17 shown in FIG.

Further, as shown in FIG. 7, a blowing pipe 19 having a plurality of blowing ports 18 on a side face is inserted into a glass tube, and the amount of blowing from each blowing port 18 is optimized to obtain a uniform thickness. Can be applied in a short time.

In the above embodiment, Y ₂ O ₃ is used as the protective film.
Although the case where a film was used was shown, if the material is transparent to ultraviolet light of 254 nm and suppresses the adhesion of mercury ions,
The effect of suppressing the mercury consumption of the fluorescent lamp is obtained. For example, aluminum oxide, tin oxide, silicon oxide, hafnium oxide, zirconium oxide, vanadium oxide, titanium oxide,
Tantalum oxide, niobium oxide, or the like can be used.

[0025]

As described above, the present invention provides mercury by providing a protective film on the surface of a phosphor layer formed on the inner surface of a glass tube without penetrating inside the phosphor layer. It is possible to provide a fluorescent lamp capable of suppressing consumption, reducing the amount of mercury used, and suppressing a decrease in luminous flux.

Further, according to the method for manufacturing a fluorescent lamp of the present invention, a protective film can be formed only on the surface of the phosphor layer and in the vicinity thereof, so that the amount of mercury used is reduced and the reduction in luminous flux is suppressed. Fluorescent lamps can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view of a fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a partially cutaway sectional view of a fluorescent lamp according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining a method of manufacturing a fluorescent lamp according to one embodiment of the present invention.

FIG. 4 is a view for explaining another method of manufacturing the fluorescent lamp according to the embodiment of the present invention;

FIG. 5 is a view for explaining another method of manufacturing the fluorescent lamp according to the embodiment of the present invention;

FIG. 6 is a view showing a diffusion plate used for manufacturing a fluorescent lamp according to an embodiment of the present invention.

FIG. 7 is a view showing a blow-out tube used for manufacturing a fluorescent lamp according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent lamp 2, 8 Glass tube 3 Phosphor layer 4 Protective film 7 Phosphor particles 9, 15, 18 Outlet 10 Suction tube 12 Double structure outlet 14, 19 Outlet tube

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Moriko Kono 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics Corporation Inside (72) Yoshio Yamaguchi 1-1, Yukicho, Takatsuki-shi, Osaka Matsushita Electronics F-term (reference) in Industrial Co., Ltd. 5C043 AA03 CC09 CD01 DD36 EA11 EB18

Claims (7)

[Claims] 1. A fluorescent lamp in which a protective film is provided on a phosphor layer formed on an inner surface of a glass tube without penetrating inside the phosphor layer. 2. A method of spraying a solution of a metal alkoxide or a metal carboxylate having a viscosity of 3 cp or more and 50 cp or less in a mist form from one end opening of a glass tube having a phosphor layer formed on an inner surface thereof. A method for producing a fluorescent lamp, wherein the solution is applied on a layer. 3. The method according to claim 2, wherein the solution contains hydroxypropyl cellulose or polyethylene oxide. 4. The method for manufacturing a fluorescent lamp according to claim 2, wherein the solution is blown into the glass tube in a mist while rotating the glass tube around a tube axis. 5. An air outlet having a first air outlet and a second air outlet formed outside the first air outlet is located near an opening of the glass tube, and 4. The method of manufacturing a fluorescent lamp according to claim 2, wherein the solution is atomized and blown into the glass tube from an outlet, and a gas containing no solution is blown into the glass tube from the second outlet. 6. Instead of spraying the solution in the form of a mist from one end opening of the glass tube, the solution is sprayed in a mist from an outlet located inside the glass tube, and the outlet and the glass are The method according to claim 2, wherein the solution is applied to an inner surface of the glass tube by relatively moving the tube in a tube axis direction. 7. Instead of spraying the solution in the form of a mist from one end opening of the glass tube, an outlet tube having a plurality of outlets on a side face is inserted into the glass tube, and the solution is supplied from the plurality of outlets. The method according to claim 2, wherein the solution is applied to the inner surface of the glass tube by spraying the solution in a mist.