JP4401329B2 - Manufacturing method of fluorescent lamp - Google Patents

Description

The present invention relates to a fluorescent lamp manufacturing method, and more particularly to stabilization of product quality by facilitating combustion of a thickener added to a phosphor in a baking process.
Hereinafter, although it demonstrates using a compact fluorescent lamp, this invention is applied also to other fluorescent lamps which have a bending part in light emission tubes, such as a bulb-type fluorescent lamp.

  FIG. 7 is a diagram showing an example of a process before mounting a base in a conventional method for manufacturing a six-column compact fluorescent lamp. First, a linear glass tube is cut into a predetermined length (S1). Next, the cut glass tube is bent (bent) into a U-shape (S2). The U-shaped tube is washed and dried (S3). A solution in which aluminum oxide fine powder is dispersed in water is applied to the inner surface of the U-shaped tube and dried (S4). A phosphor coating solution is applied and dried (S5). The phosphor is baked and the thickener is burned (S6). Seal each U-tube. A stem having an electrode is sealed in two U-shaped tubes, and a stem having only an exhaust tube is sealed in the other U-shaped tube (S7). One of the U-shaped tubes having electrodes and the U-shaped tube having only the exhaust pipe are joined (S8). This is joined to another U-tube having electrodes (S9).

  In conventional fluorescent lamps such as compact fluorescent lamps, when forming a layer of fluorescent material in a glass tube, a dispersion is prepared by dispersing the fluorescent material in water, and a binder or a surface active agent is added to the lacquer. The viscosity is adjusted using a so-called thickener (for example, polyethylene oxide), and the phosphor film thickness is uniform and uniform in each part of the fluorescent lamp when the fluorescent lamp is completed. The thickener is then heated and burned in the baking process. Therefore, in the baking process, the lacquer used for forming a uniform and homogeneous phosphor film in the coating process is decomposed and gasified, and removed from the phosphor layer.

In a compact fluorescent lamp composed of a U-shaped tube, the phosphor coating liquid is applied, dried and baked as shown in FIG. That is, in the baking process, the bent portion 2b of the U-shaped tube 2 is suspended by the hook 5, and the baking is performed with the bent portion 2b on the upper side and the open end 2c on the lower side.
JP-A-8-17334

  In the conventional compact fluorescent lamp, the phosphor is baked as described above. However, in order to sufficiently burn the lacquer in the baking process, it is necessary to supply oxygen and manage the furnace temperature. In addition, the baking process is performed as shown in FIG. 8, for example. When the bent portion 2b is on the upper side and the open end 2c is on the lower side, the convection of the air in the pipe is reduced particularly when the pipe diameter is thin and long. Since it deteriorates, the supply of oxygen into the pipe may be insufficient, or the temperature in the pipe may not reach the temperature until the lacquer is burned. This phenomenon does not occur so much with a thick and short U-tube 2 up to a four-column compact fluorescent lamp. In the 6-column compact fluorescent lamp, the U-shaped tube 2 is narrower and longer than the 4-column, and therefore there is a tendency for lacquer to be insufficiently burned in the phosphor baking process.

  The phosphor baking process is generally called a tunnel furnace. A chain conveyor passes through the oven, and the U-tube 2 coated with the phosphor coating liquid is carried on the conveyor while being transported. Heated. However, in order to bake sufficiently, it is sufficient to raise the temperature and slow down the conveyor, but there is a possibility that the glass melts and deforms. On the other hand, in order to avoid this danger, if the temperature is lowered or the speed of the conveyor is increased, the baking will be insufficient, and the organic content of the lacquer will remain in the phosphor layer, resulting in partial tar formation and characteristics at the time of lamp completion, There was a problem of deteriorating the deterioration characteristics.

  The present invention has been made to solve the above-described problems. Since the tube has a bent portion, the tube diameter is thin, and the tube is long, the increase in the phosphor is included in the phosphor baking process. It is an object of the present invention to provide a method for manufacturing a fluorescent lamp in which a sticking agent can easily burn.

  In the method for manufacturing a fluorescent lamp according to the present invention, a plurality of lamp tube elements having bent portions are joined to form an arc tube, the tube inner diameter of the lamp tube element is 13 mm or less, and the length of one lamp tube element is 100 mm. In the fluorescent lamp manufacturing method described above, at least a thickener is used, and a phosphor coating liquid whose viscosity is adjusted by the thickener is used to apply and dry the inner surface of the lamp tube element, and ultraviolet rays are applied to the lamp tube element. It is characterized by comprising a step of irradiating and a baking step of burning and decomposing the thickener to form a phosphor layer.

  The fluorescent lamp manufacturing method according to the present invention is characterized in that ultraviolet rays are irradiated from the opening end of the lamp tube element.

  The fluorescent lamp manufacturing method according to the present invention is characterized in that baking is performed to form a phosphor layer with the bent portion of the lamp tube element facing upward.

  The fluorescent lamp manufacturing method according to the present invention is characterized in that the thickener is polyethylene oxide.

  The fluorescent lamp manufacturing method according to the present invention is characterized in that the step of irradiating ultraviolet rays is provided in a manufacturing line.

  In the fluorescent lamp manufacturing method according to the present invention, by applying ultraviolet light to the phosphor layer before the baking process, the thickener in the coated and dried phosphor layer is easily burned, and oxygen is supplied in the baking process. Even if the baking temperature fluctuates, the product characteristics are stabilized.

Embodiment 1 FIG.
1 to 6 are diagrams showing the first embodiment. FIG. 1 is a diagram showing an overall configuration of a compact fluorescent lamp 1 having six pillars. FIG. 2 is a cross-sectional view of a U-shaped tube 2. FIG. The figure which shows the manufacturing process before mounting | wearing with the nozzle | cap | die of the compact fluorescent lamp 1, FIG. 4 is the figure which shows the ultraviolet irradiation method to the U-shaped tube 2, FIG. 5 is the figure which shows the effect confirmation test result of the ultraviolet irradiation before fluorescent substance baking FIG. 6 is a view showing a modification of the arc tube.

  As shown in FIG. 1, a compact fluorescent lamp 1 (an example of a fluorescent lamp) has three U-shaped tubes 2 (an example of a lamp tube element) each having a bent portion 2b and end side walls (joint portion 2a). ), The arc tube 10 in which a meandering discharge path is formed as a whole by six glass bulbs, and a flat portion 3b to which the arc tube 10 is fixed by bonding or the like and the flat portion. A base case 3 having a side wall 3a having a hexagonal cross section connected to the portion 3b, and a base 4 having a base pin 4a that fits into the base case 3 and is electrically connected to a lead wire from the arc tube 10. With.

The bent portion 2b of the U-shaped tube 2 is formed by bending or joining. FIG. 2 is a cross-sectional view of the U-shaped tube 2 that is a lamp tube element.
L = length of U-shaped tube 2 D1 = inner diameter of U-shaped tube 2 D2 = defined as outer diameter of U-shaped tube 2

  The features of the embodiment of the present invention will be described with reference to FIG. The difference from the manufacturing process before mounting the base of the conventional 6-pillar compact fluorescent lamp described in FIG. 7 is that the phosphor coating liquid is applied and dried (S5), and the phosphor baking process (S6). The step (S10) of irradiating ultraviolet rays from the opening end portion 2c of the U-shaped tube 2 is provided. The other steps are the same as those shown in FIG. Since the process of irradiating with ultraviolet rays is provided in the production line, productivity is not hindered. Further, in the phosphor baking step (S6), the baking is basically performed with the open end 2c of the U-shaped tube 2 at the bottom and the bent portion 2b at the top. For example, baking is performed on the hook 5 shown in FIG. However, the present invention is not limited to this, and the present invention includes a case where baking is performed in another posture.

  In the step of irradiating ultraviolet rays from the open end 2c of the U-shaped tube 2, as shown in FIG. 4, the ultraviolet rays are directed toward the open end 2c of the U-shaped tube 2 so that the ultraviolet rays are directly irradiated to the phosphor. Irradiation is preferred. However, it may be from other directions, and has substantially the same effect. It is considered that the ultraviolet light irradiated into the U-shaped tube 2 from the opening end 2c is reflected by the phosphor layer and diffuses into the tube.

  Next, in order to confirm the effect of ultraviolet irradiation of S10, a prototype with and without ultraviolet irradiation was made, and the total light flux and blackening in the vicinity of the electrode were verified. The lamp used for the test is a six-pillar compact fluorescent lamp 1 of model name FHT42EX-N. A 400 W metal halide lamp was used for ultraviolet irradiation. The tubes coated with the phosphor coating solution were arranged in a box with the opening end facing upward, and irradiated with a 400 W metal halide lamp from above for about 2 hours. Then, the total luminous flux (lm) after 100 hours of lighting and blackening after 2000 hours of lighting were examined. The lighting time is a JIS cycle actual lighting time of 2.75 hours on-0.25 hours off. Blackening was evaluated on a scale of 0 to 5 (0: no blackening, ... 5th grade: complete blackening). Furthermore, the lamp used in the test has the same manufacturing conditions and specifications, and only the phosphor baking temperature is changed by 5% (the normal condition is a baking temperature of 550 ° C, and the abnormal condition is a baking temperature of 520 ° C). is there). The result is shown in FIG. The conventional example of FIG. 5 is one without ultraviolet irradiation, and the present invention is one with ultraviolet irradiation.

  As shown in FIG. 5, there is no difference between the conventional example and the present invention in terms of the total luminous flux in the initial stage of lighting and the total luminous flux after 100 hours of lighting, when burned under normal conditions (550 ° C.). If baking is performed under normal conditions, the polyethylene oxide that is a thickener burns without being irradiated with ultraviolet rays.

  In the case of baking under abnormal conditions (520 ° C.), in the conventional example in which ultraviolet rays are not irradiated, the total luminous flux is reduced to an average of 96% even at the beginning of lighting as compared with the embodiment of the present invention in which ultraviolet rays are irradiated.

  Furthermore, when the total luminous flux at the beginning of lighting in the embodiment of the present invention is 100%, the total luminous flux of the present invention irradiated with ultraviolet rays is 96% after 100 hours of lighting, whereas the conventional luminous flux is not irradiated. In the example, the total luminous flux is reduced to 92%. The conventional example which does not irradiate ultraviolet rays is considered that the polyethylene oxide which is a thickener is not burned out completely.

  Further, the blackening after 2000 hours of lighting was observed to be 2.5 grade or 3.0 grade blackening only in the conventional examples which were baked under abnormal conditions (520 ° C.) and not irradiated with ultraviolet rays.

  In the embodiment of the present invention, before the baking step of burning lacquer which is an organic substance, the phosphor layer is irradiated with ultraviolet rays, so that polyethylene oxide which is a lacquer component is decomposed by ultraviolet rays, and a linear chain of polyethylene oxide is formed. It is assumed that it is cut and the molecular weight is reduced, and it becomes easy to burn in the baking process.

  The glass tube of the 6-column compact fluorescent lamp 1 (example of 42 W) has a tube outer diameter D2 of 12.3 mm, a tube inner diameter D1 of 10.8 mm, and a length L of the U-shaped tube 2 of 98.3 mm.

  The glass tube of the compact fluorescent lamp 1 with four pillars, which is unrelated to the problem of incomplete combustion of the thickener, has a tube outer diameter D2 of 16.5 mm, a tube inner diameter D1 of 15.0 mm, and the length of one U-shaped tube 2. The length L is 109 mm (18 W) and 121 mm (27 W).

  Therefore, the present invention is effective when the tube inner diameter D1 is 13 mm or less and the length L of the U-shaped tube 2 is 100 mm or more.

  The present invention is also effective for a lamp using a double spiral arc tube 20 as shown in FIG.

FIG. 2 is a diagram illustrating the first embodiment and is a diagram illustrating an overall configuration of a six-column compact fluorescent lamp 1. FIG. 5 shows the first embodiment and is a diagram showing an example of a bent portion of a U-shaped tube 2. It is a figure which shows Embodiment 1, and is a figure which shows the manufacturing process before mounting | wearing with the nozzle | cap | die of the compact fluorescent lamp 1 of 6 pillars. FIG. 5 shows the first embodiment and is a diagram showing a method of irradiating the U-shaped tube 2 with ultraviolet rays. It is a figure which shows Embodiment 1, and is a figure which shows the effect confirmation test result of the ultraviolet irradiation before fluorescent substance baking. It is a figure which shows Embodiment 1 and is a figure which shows the modification of an arc tube. It is a figure which shows an example of the process before mounting | wearing with a nozzle | cap | die of the manufacturing method of the conventional compact fluorescent lamp of 6 posts. It is a figure which shows the fluorescent substance coating liquid application | coating, drying, and baking process of the conventional compact fluorescent lamp.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compact fluorescent lamp, 2 U-shaped tube, 2a joint part, 2b bending part, 2c opening end part, 3 base case, 3a side wall, 3b flat part, 4 base, 4a base pin, 5 hook, 10 arc tube, 20 2 Double spiral arc tube.

Claims (5)

In a method for manufacturing a fluorescent lamp, a plurality of lamp tube elements having a bent portion are joined to form an arc tube, the tube tube inner diameter is 13 mm or less, and the length of the lamp tube element is 100 mm or more.
Using a phosphor coating liquid containing at least a thickener and adjusting the viscosity with this thickener, applied and dried on the inner surface of the lamp tube element ,
Irradiating ultraviolet radiation to the lamp tube element,
Decomposed by burning the thickener, fluorescent lamp manufacturing method of characterized the Turkey to form a phosphor layer.   2. The method of manufacturing a fluorescent lamp according to claim 1, wherein ultraviolet rays are irradiated from an opening end of the lamp tube element.   2. The method of manufacturing a fluorescent lamp according to claim 1, wherein baking is performed to form the phosphor layer with the bent portion of the lamp tube element facing upward.   2. The method of manufacturing a fluorescent lamp according to claim 1, wherein the thickener is polyethylene oxide. The irradiation of the ultraviolet to the lamp tube element, a fluorescent lamp manufacturing method of claim 1, wherein the performing similar production line.

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