JPS6226133B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a reflective fluorescent lamp, in particular,
The present invention relates to a method for manufacturing a reflective fluorescent lamp in which a reflective layer made of a fluorescent substance is provided on the discharge path side.

A typical fluorescent lamp has a single phosphor coated to a substantially uniform thickness on the inside wall of a glass tube. In such a conventional fluorescent lamp, a substantially uniform luminous flux distribution is obtained in the radial direction from the center of the glass tube. However, in practice, the light beam in the main irradiation direction, which is a specific radial direction from the center of the glass tube, is mainly used.
A reflective fluorescent lamp has been proposed as a fluorescent lamp for this purpose. This is achieved by providing a reflective coating such as titanium oxide on the inner wall of the glass tube on the side opposite to the main irradiation direction of the fluorescent lamp, and further forming a phosphor coating on the entire inner surface.
The aim is to obtain strong illuminance directly below the lamp by irradiating the light flux generated inside the glass tube in a concentrated manner from the light-transmitting surface at the bottom of the tube. A technique using apatite as a reflective coating is disclosed in Japanese Patent Publication No. 36-7689. This is based on the fact that apatite absorbs far less ultraviolet rays than titanium oxide, and is intended to improve the luminous efficiency of the lamp. Further, a technique using a phosphor as a reflective coating is disclosed in Japanese Patent Publication No. 36-22794. This is because the phosphor absorbs far less ultraviolet rays than titanium oxide, which improves the luminous efficiency of the lamp, and the phosphor for the reflective coating can also be used as the phosphor for the coated coating that is then applied to the entire surface. This is also intended for manufacturing convenience. 2 mentioned above
In general, the reflective coating is applied to the inner surface of the glass tube approximately 230 mm above the circumference within its cross-section, including two conventional examples.
Formed over time.

However, the manufacturing process of the conventional reflective fluorescent lamp described above includes (1) a reflective film coating process using a reflective film substance coating liquid (see layer 2 in Figure 3), and (2) a drying process (20° to 100°). ℃), (3) Baking process (550° to 650°C), (4) Fluorescent coating process using a fluorescent coating material coating liquid (see layer 3 in Figure 3), (5) Drying process (20° to 650°C). (100℃), (6) Firing process (550℃ to 650℃) It had the disadvantage of significantly impairing the In other words, by requiring a firing process for the reflective film, the time required to complete the process, equipment such as machinery, floor space occupied, manpower, etc. all increase, making it extremely difficult not only in terms of mass production but also in terms of cost. I was facing it.

Therefore, an object of the present invention is to provide a novel method for manufacturing a reflective fluorescent lamp that solves the above-mentioned problems in the conventional manufacturing process, that is, it can omit the firing step after the first layer of two-layer coating. Our goal is to provide the following.

In order to achieve the above object, in the present invention, a phosphor is first coated on the entire inner surface of a glass tube, and after drying, a part of the phosphor is coated with a reflective film in an unfired state. The method is characterized in that a reflective fluorescent lamp is manufactured by applying the phosphor, drying it, and then firing the entire phosphor.

Through such a characteristic manufacturing process of the present invention,
It has become possible to omit the step of firing the phosphor that is initially applied without leaving any negative effects on the appearance or illuminance of the lamp. As a result, by requiring only one firing process, the time required from the first coating process to the final firing process in the conventional process was approximately 50 minutes, but the manufacturing process according to the present invention shortened the time by approximately 20 minutes. This was possible in about 30 minutes. Furthermore, the process of returning the glass tube from the initial firing process to the reflective coating coating process, which was necessary in the conventional process, is completely unnecessary, and there is no need to consider mechanical equipment or human work. , it was possible to improve mass productivity and reduce costs.

Hereinafter, the present invention will be explained in detail using the drawings.
First, in comparing a reflective fluorescent lamp manufactured by the manufacturing method according to the present invention with a reflective fluorescent lamp manufactured by a conventional manufacturing method,
The differences in the manufacturing process will be described below. FIG. 1 shows the external appearance of a reflective fluorescent lamp according to the present invention.
FIG. 2 is an enlarged cross-sectional view of the reflective fluorescent lamp shown in FIG. 1 taken along line XX (the mount portion is not shown). Furthermore, FIG. 3 is an enlarged cross-sectional view of a conventional reflective fluorescent lamp.
It is shown for reference only. The method for manufacturing a reflective fluorescent lamp according to the present invention will be described with reference to FIGS. 1 to 3. a step of applying a phosphor to form a first phosphor layer 4; (2) a step of drying the layer 4 in an atmosphere of 20 to 100°C; With layer 4 in an unfired state, a second phosphor layer 5 is formed by applying a phosphor suspension having a viscosity similar to that of layer 4 to an area of about 230 degrees above the inside of the layer. (4) Next, the step of drying the layer 5 in an atmosphere of 20 to 100° C.; (5) Finally, the step of firing the layers 4 and 5 in a firing furnace. All you have to do is go through the steps. On the other hand, the lamp shown in FIG. 3, which was manufactured using a conventional manufacturing process, required six manufacturing steps as already mentioned in the prior art section. This difference in the number of steps is caused by the presence or absence of a baking step after the initial film formation (hereinafter referred to as the first layer baking step). Next, an experiment and its results regarding this reason will be shown. First, the following four types of reflective fluorescent lamps (FL-40S) are manufactured.

Type A: Lamp type B manufactured using the conventional manufacturing process (with a reflective film as the first layer and a first layer firing process): Lamp type C manufactured using the conventional manufacturing process by omitting the first layer firing process : Lamp type D manufactured by adding a first layer firing step to the manufacturing process of the present invention: Lamp manufactured by the manufacturing process of the present invention Next, the above four types of reflective fluorescent lamps are lit, The boundary line between the reflective layer (the phosphor layer in the overlapping part of the first layer and the second layer) and the transmitting layer (the phosphor layer in the part other than the reflective layer) (drawer number 6 in Figure 1) ) Visually observe the surrounding area. A state in which the boundary line 6 can clearly distinguish between the reflective layer and the transmitting layer is defined as "good appearance", and a state in which it is almost impossible to distinguish where the boundary line exists (W (described later) in Figure 4b is 2 mm or more) It is also judged based on the criterion of “defect in appearance”. The result was as follows.

Type A: “Good appearance” Type B: “Poor appearance” Type C: “Good appearance” Type D: “Good appearance” In other words, only type B lamps (without the first layer firing step in the conventional manufacturing process) are visible. As a result of observation, it was found to have a "defect in appearance." When we investigated the reason for this, we came to the following conclusion. Type A lamps include a layer 2 firing process, so
When observed from the visual observation direction A as shown in FIG. 4a, the boundary line 6 between the reflective layer and the transparent layer can be clearly distinguished. However, as shown in Figure 4b,
In the case of type B lamps, the firing step of layer 2 is omitted, so that the binder contained in the subsequently applied layer 3 affects layer 2 and results in melting of the edges of layer 2. The boundary line 6 becomes unclear (a sag width W of about 10 mm from the end that should be the end) occurs. On the other hand, in the manufacturing process according to the present invention, when the first layer firing step is further added, and in the case of the manufacturing process according to the present invention, the fourth layer
As shown in Figures c and d, there is no effect at all between type C and D lamps due to the presence or absence of the first layer firing process. This is because even if the firing step of the first layer, that is, layer 4, is omitted, the edges of layer 5 will collapse due to the surface tension of layer 5 or because layer 5 is applied only to a part of the surface of layer 4. It is considered that the phenomenon will not occur. As a result, when observed from the visual observation direction A, the boundary line 6 can be clearly observed.

It has been recognized that the negative impact on lamps caused by omitting the first layer firing step in the conventional manufacturing process is not only the above-mentioned appearance problem, but also subtly affects the light distribution characteristics and direct illuminance. Ta.

Next, a specific example of the method for manufacturing a reflective fluorescent lamp according to the present invention will be described.

Calcium halophosphate phosphor activated with antimony and manganese 50Kg with 1.0% nitrified cotton butyl acetate 70
The mixture is ground and mixed in a ball mill for 1 hour to form a suspension. Next, (1) apply the suspension to the entire inner wall of the glass tube to form a fluorescent film layer (approximately 3.8
mg/cm ² ). Then, (2) dry in an atmosphere of 20 to 100°C. Next, (3) the above-mentioned phosphor suspension is applied over a part of the circumference at about 230 degrees to form a phosphor reflective layer (approximately 3.8 mg/cm ² coating amount). Then, (4) after drying in an atmosphere of 20 to 100℃, (5) approx.
A fluorescent film is formed by baking at 600°C for about 5 minutes. Thereafter, according to conventional methods, the lamp is mounted, sealed, evacuated, filled with Hg and gas, and sealed to complete the reflection type fluorescent lamp FL-40S.

The reflection type fluorescent lamp according to the above embodiment and the reflection type fluorescent lamp according to the conventional manufacturing process (the lamp shown in Fig. 3 uses a phosphor as layer 2, and the amount of phosphor coating is as described above) The performance was evaluated by comparing the FL-40S of a general type fluorescent lamp (same as above) and a general type fluorescent lamp (the amount of phosphor coating was approximately 4.6 mg/cm ² ). The direct illuminance at a distance of 3 m from the center of each lamp is 140 lux for the lamp according to the above embodiment (type D), and 140 lux for the conventional lamp (type B).
was 125 lux, and a general type lamp was 100 lux. As a result, in the reflective fluorescent lamp according to the above embodiment, even if the first layer firing process is omitted, the boundary line between the reflective layer and the transmitting layer appears clearly, and in terms of direct illuminance, the reflection compared to the conventional manufacturing method is achieved. It can be seen that its performance is much better than that of a fluorescent lamp.

In addition, in the above-mentioned embodiment, the first layer and the second layer
Although the description has been made assuming that the phosphors and the layer have the same composition, it is not necessary that the phosphors have the same composition, and it goes without saying that the manufacturing method of the present invention can be applied to a combination of phosphors with different compositions. . In this case, the effect of improving color rendering properties can be obtained due to the color mixing effect. Furthermore, although the coating angle of the second layer of fluorescent material has been described as approximately 230 degrees, it is not limited to this angle and may be any angle depending on the use of the reflective fluorescent lamp.

In addition, since the reflective fluorescent lamp manufactured by the manufacturing process of the present invention uses a phosphor as a reflective layer, in the tube bending process for manufacturing the annular reflective fluorescent lamp, This method has the advantage that it can be handled almost in the same way as the tube bending process for general fluorescent lamps.

As described above, by the method for manufacturing a reflective fluorescent lamp according to the present invention, it is possible to manufacture a reflective fluorescent lamp with excellent appearance and direct illuminance through the simplest manufacturing process with high productivity and at low cost. Therefore, the industrial benefits are extremely large.

[Brief explanation of the drawing]

Fig. 1 is an external view of a reflective fluorescent lamp manufactured according to the present invention, Fig. 2 is an enlarged view of the XX cross section shown in Fig. 1, and Fig. 3 is an external view of a reflective fluorescent lamp manufactured by the conventional manufacturing method. 4a, b, c, and d are explanatory views for explaining the differences in appearance depending on the presence or absence of the firing process. 1: Glass tube, 2, 5: Reflective film, 3, 4: Fluorescent film, 6: Boundary line.

Claims (1)

[Scope of Claims] 1. A first coating step of coating the first phosphor on the entire inner surface of the glass tube, and a first coating step of drying the first phosphor after the first coating step. a drying step, a second coating step of applying a second phosphor to a partial area on the coating surface of the first phosphor in an unfired state after the first drying step; After the coating step, a second drying step of drying the second phosphor, and a second drying step of drying the second phosphor;
A method for manufacturing a reflective fluorescent lamp, comprising a step of firing the first and second phosphors after the drying step. 2. The method of manufacturing a reflective fluorescent lamp according to claim 1, wherein the first phosphor and the second phosphor have the same composition. 3. A method for manufacturing a reflective fluorescent lamp according to claim 1, wherein the first phosphor and the second phosphor are phosphors having different compositions.