JP3523367B2 - Manufacturing method of straight tube fluorescent lamp - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straight fluorescent lamp manufactured in a horizontal production line and a method of manufacturing the same. 2. Description of the Related Art In recent years, the consciousness of consumers for lighting has been improved, and the era has come to the point where manufacturers must produce even higher quality products. For example, the quality of a phosphor layer, such as "unevenness", which does not affect the basic characteristics of the lamp such as brightness at all, is determined based on a stricter standard than before. On the other hand, there is a horizontal type production system in which lamps are horizontally produced at a high speed in order to increase the production capacity of fluorescent lamps. Since the processing of both ends of the lamp can be performed at the same time, the time required for production can be shortened and the speed can be increased. [0003] However, since the lamp is produced while being held horizontally, the mercury sealed in the lamp rolls on the phosphor layer depending on the temperature of the lamp, and the black mark of the mercury occurs. There was a problem of leaving.
More specifically, when the temperature of the glass bulb is high, a small amount of mercury particles sealed in the evacuation process adheres to the contact portion with the phosphor layer. Therefore, there is no particular problem if the mercury particles do not move, but when the glass bulb rotates, the mercury particles move, and with the rotation of the glass bulb, a black circle of mercury is drawn on the phosphor layer. Naturally, in a vertical production line, the above problem does not exist because the mercury particles are at one end of the lamp. Also, even in a horizontal production line, if the temperature at the time of mercury filling is low, even if mercury particles roll on the phosphor layer, no black mark will be formed. Also, as described above, if the lamp does not rotate, the mercury naturally does not move, and a black ring does not occur. Since this ring is made of a small amount of liquid mercury, if the lamp is turned on for about 30 minutes after completion of the lamp, it evaporates and disappears due to a rise in temperature due to self-heating of the lamp. [0004] However, there are two major problems related to this. One of the causes was that the "ring" itself had significantly impaired its appearance, and when consumers turned on the product after purchasing it, they perceived it as dirty as if it had been marked with a pencil. Another drawback is that the inspector on the production line sees this ring and mistakes it for a broken or cracked glass bulb. And
Although the product thus determined is a good product, it is discarded, resulting in a great loss. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and suppresses the formation of mercury rings in the initial stage of lighting and in the manufacturing process, thereby reducing the occurrence of product claims and the loss during manufacturing. It is an object of the present invention to provide a tubular fluorescent lamp and a method for manufacturing the same. [0006] In the straight tube fluorescent lamp according to the present invention, the temperature of the glass bulb in the mercury filling step is 90 ° C or more, and the temperature of the glass bulb reaches 90 ° C after mercury filling. Before the glass bulb is lowered, the glass bulb is a straight tube type fluorescent lamp manufactured through a process of rotating while being held horizontally, in which an aluminum oxide film is provided between the glass bulb and the phosphor layer. Further, the amount of the oxide film deposited was 0.1 mg / cm ² to 0.4 mg / cm ^2.
cm ² . Further, an aluminum oxide film is provided in advance between the phosphor layer of the glass bulb and the phosphor layer to manufacture the glass bulb. In the straight tube fluorescent lamp constructed as described above, although the reason is unknown, it has been experimentally confirmed that an aluminum oxide film was formed on the glass bulb. It is thought that the formation of black rings due to mercury is suppressed in connection with the charging of the toner. Also,
By controlling the adhesion amount of the aluminum oxide coating in the range of 0.1 mg / cm ² to 0.4 mg / cm ² , the mercury ring is effectively suppressed. Further, by providing the aluminum oxide coating between the glass bulb and the phosphor layer in advance, a straight tube fluorescent lamp free of mercury rings can be easily manufactured. An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 1 denotes a glass bulb of a 40 W type straight tube fluorescent lamp (FL40S), which is made of soda-lime glass. Reference numeral 2 denotes an aluminum oxide coating applied to the inner surface of the glass bulb 1, which is obtained by dispersing an aluminum oxide coating material manufactured by Degussa Co., Ltd. in water, coating and drying. Reference numeral 3 denotes a phosphor layer adhered on the aluminum oxide film 2 and 4 denotes electrodes hermetically sealed at both ends of the glass bulb 1. Reference numeral 5 denotes a valve conveying device, which has a guide rail 6 having an inclination in which a feed direction side is downward;
A chain conveyor 8 provided with a transfer claw 7 is provided. As described above, the glass bulb 1 provided with the aluminum oxide coating between the glass bulb 1 and the phosphor layer 3 in advance is held horizontally, while being heated so that the maximum temperature is about 400 ° C. Exhaust processing is performed in an exhaust step by an ordinary fluorescent lamp manufacturing method. At this time, the inside of the glass bulb 1 is filled with a rare gas such as argon gas and 5 to 20 when the temperature of the glass bulb 1 becomes about 250 ° C.
Mercury particles appropriately weighed to about mg are enclosed. Then, the glass bulb 1 after the evacuation process is conveyed to the next step while rotating slowly by the valve conveying device 5 while being gradually cooled. In this step, the glass bulb 1 has been rotated several times until its temperature drops to 90 ° C. [0010] The incidence of black rings of mercury in the manufactured straight tube fluorescent lamp was examined by changing the type of coating material and the amount of the coating, and the results shown in FIG. 2 were obtained. . As can be seen from FIG. 2, the effect of suppressing the mercury ring appears only in aluminum oxide. In particular, in order to obtain a substantial effect, the adhesion amount is 0.1 mg / cm ² to 0.4 mg / cm ^2. A range of ² is desirable. 0.1
When the amount is less than mg / cm ² , a substantial effect cannot be obtained. When the amount exceeds 0.4 mg / cm ² , although there is an effect of suppressing mercury rings, the strength of the phosphor layer film is remarkably reduced, causing another problem. . Now, aluminum oxide was tested by various manufacturers, and a similar effect was obtained. Also, the type of lamp is not limited to the 40 W type of the above embodiment, and the present invention is also effective for a small lamp such as 10 W to a large lamp such as 110 W. The provision of an aluminum oxide coating on the inner surface of a glass bulb is disclosed, for example, in Japanese Patent Laid-Open No. 58-2163.
No. 35 is also known. However, the conventional aluminum oxide coating is mainly intended to improve the luminous flux deterioration, and as in the present invention, it is effective in suppressing mercury rings generated under the conditions of the characteristics of a horizontal production line. Nothing is disclosed. Further, in the above embodiment, an example has been described in which the glass bulb 1 is rotated by the valve transport device 5 after the exhaust process is completed. However, the rotation of the glass bulb is not limited to the rotation by the valve transport device. If the temperature of the glass bulb is not lowered to 90 ° C., it is a matter of course that the glass bulb may be rotated in a capping process after the exhaust process. As described above, according to the present invention, the glass bulb is held horizontally while the temperature of the glass bulb is reduced to 90 ° C. after the completion of the filling of mercury into the glass bulb in the evacuation step. An aluminum oxide film is provided between the glass bulb and the phosphor layer to rotate around the central axis, thereby suppressing the formation of black rings due to mercury generated during the initial stage of lamp operation and during the lamp manufacturing process. As a result, the loss of disposing of product claims and non-defective products being manufactured as defective products can be greatly reduced. Further, since the adhesion amount of the aluminum oxide film is in the range of 0.1 mg / cm ² to 0.4 mg / cm ² , the generation of a black ring of mercury can be more effectively suppressed. Furthermore, since the aluminum oxide film is provided in advance between the glass bulb and the phosphor layer and manufactured, there is an effect that a straight tube-type fluorescent lamp without generation of a black ring of mercury can be easily manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing experimental results of the present invention. [Description of Signs] 1 Glass bulb, 2 aluminum oxide coating, 3 phosphor layer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 61/35 H01J 9/20

Claims (1)

(57) [Claim 1] A step of holding a glass bulb horizontally and filling mercury in the glass bulb when the temperature of the glass bulb is 90 ° C. or more. Before the temperature of the glass bulb decreases to 90 ° C., a method of manufacturing a straight tube fluorescent lamp having a step of rotating the glass bulb held horizontally in one or more rotations around its central axis. A method for manufacturing a straight tube fluorescent lamp, wherein an aluminum oxide coating is provided between the fluorescent layer and the phosphor layer.