JPS644306B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to fluorescent lamps.

In a conventional fluorescent lamp, as shown in FIG. 1, a phosphor layer 2 is formed by uniformly applying a phosphor on the inner circumferential surface of a lamp tube 1 in a planar manner. However, this fluorescent lamp, as shown in Figure 2,
Since the phosphor layer 2 is formed of phosphors 3 that are tightly packed together, there is a problem in that the light efficiency is poor. That is, as shown in FIG. 1, the ultraviolet rays 4 generated at point A in the lamp tube 1 are reflected at a certain probability on the surface of the phosphor layer 2, and the loss due to this reflection is as high as 10 to 20%. This is the primary cause of poor light efficiency. The second cause of poor light efficiency is as follows. Generally, the conversion from ultraviolet light (253.7 nm) to visible light occurs at the very surface of the phosphor layer 2.
The further inside the phosphor layer 2, the weaker the light becomes. On the other hand, the phosphor 3 has a high reflective ability for visible light. Therefore, most of the light converted from ultraviolet rays 4 to visible light is reflected many times by the phosphor 3 and reaches the lamp tube 1, and during this time the loss due to reflection increases and the light efficiency deteriorates. As described above, conventional fluorescent lamps have had the problem of poor light efficiency due to large reflection losses of ultraviolet 4 and converted visible light.

On the other hand, there were lamp tubes in which the entire interior of the lamp tube was filled with glass wool whose surface was coated with a luminescent material and which allowed discharge to pass through.
-31082), the discharge voltage becomes high because the glass wool blocks the discharge path, and the irradiation efficiency of ultraviolet rays to the luminescent material decreases because the glass wool cannot be packed too densely. The drawback was that a large amount of optical paint was required.

Therefore, an object of the present invention is to reduce ultraviolet and visible light without increasing the discharge voltage, without increasing the amount of glass wool and fluorescent paint, and without reducing the efficiency of irradiating ultraviolet light to the phosphor. An object of the present invention is to provide a fluorescent lamp which can reduce reflection loss and has good light efficiency.

An embodiment of this invention is shown in FIGS. 3 and 4. That is, this fluorescent lamp has a lamp tube 1 having a pair of electrodes (not shown), and a cylindrical tube that covers the inner peripheral surface of the lamp tube 1 and forms a discharge space between the pair of electrodes inside. hot fluorescent body 3
The phosphor 3 and the glass wool 5 form a phosphor layer 6.
In this case, the phosphor layer 6 may be formed by applying the phosphor 3 to the glass wool 5 and then inserting the glass wool 5 into the lamp tube 1.
Further, glass wool 5 is arranged inside the lamp tube 1,
It may also be formed by coating the glass wool 5 with the phosphor 3.

Because of this configuration, as shown in FIG. 4, the surface of the phosphor layer 6 becomes extremely uneven, increasing the surface area of the phosphor layer 6, and as a result, the probability of ultraviolet absorption on the surface of the phosphor layer 6 decreases. As the phosphor 3 increases,
The probability that the reflected ultraviolet rays 4 will enter the next phosphor 3 via a short path also increases, thereby reducing the reflection loss of the ultraviolet rays 4 and improving the light efficiency of the fluorescent lamp. On the other hand, compared to the conventional examples shown in FIGS. 1 and 2, the phosphor 3 is loosely arranged by the glass wool 5, so that visible light 7 converted from ultraviolet rays 4 by the phosphor 3 The number of times that the visible light 7 is reflected by the phosphor 3 before it passes between each fiber of the glass wool 5 and reaches the lamp tube 1 is reduced, thereby reducing the reflection loss of the visible light 7 and reducing the light from the fluorescent lamp. Improved efficiency. In this case, although the traveling distance of the visible light 7 to the lamp tube 1 increases compared to the conventional case, since the visible light 7 has a characteristic that its attenuation is small in argon and mercury, this increase in the traveling distance is It has little effect on the light efficiency of the fluorescent lamp. Furthermore, since the glass wool 5 reduces the discharge space capacity within the lamp tube 1, the absorption of ultraviolet rays 4 in the argon-mercury space is reduced in currently widely used 32 mm fluorescent tubes. It is also expected that the ultraviolet rays 4 will efficiently reach the phosphor 3. Furthermore, compared to the conventional example in which glass wool is filled completely inside the glass tube, the glass wool 5 is formed into a cylindrical shape and a discharge space is formed inside, so the discharge voltage does not increase and the discharge remains the same as before. It can be lit with voltage and does not require large amounts of glass wool and fluorescent paint. Moreover, since the glass wool 5 can be made dense, the irradiation efficiency of the ultraviolet rays 4 to the phosphor 3 does not decrease.

In addition, as another example of the fibrous composite body, a mesh consisting of one layer or multiple layers may be used.

As described above, the fluorescent lamp of the present invention has a cylindrical shape that includes a lamp tube having a pair of electrodes, and a discharge space that covers the inner peripheral surface of the lamp tube and forms a discharge space between the pair of electrodes. Since the present invention is equipped with a fibrous aggregate with a phosphor coated on its surface, compared to conventional examples, there is no need to increase the discharge voltage or increase the amount of glass wool and fluorescent paint. Furthermore, there is an effect that reflection loss of ultraviolet rays and visible light can be reduced and light efficiency can be increased without reducing the efficiency of irradiating the phosphor with ultraviolet rays.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional example, FIG. 2 is an enlarged sectional view of a main part thereof, FIG. 3 is a sectional view of an embodiment of the present invention, and FIG. 4 is an enlarged sectional view of a main part thereof. 1... Lamp tube, 3... Fluorescent material, 5... Glass wool (fibrous aggregate).

Claims (1)

[Claims] 1 A lamp tube having a pair of electrodes, and a cylindrical body that covers the inner peripheral surface of the lamp tube and forms a discharge space between the pair of electrodes on the inside, and has a fibrous material coated on its surface. A fluorescent lamp comprising a composite body.