JPS5893155A - Discharge lamp - Google Patents

Abstract

PURPOSE:To prevent reduction of the luminous efficiency by forming the coldest part at the top of the return part of a U-shaped discharge lamp by setting the ratio L/D related to the length L of the diameter at the return part and the diameter D of the bulb to 1.2-3, and controlling the mercury vapor pressure in the lamp within the optimum operation range. CONSTITUTION:As the ratio L/D related to the length L of the diameter of the return part 4 of a U-shaped discharge tube and the diameter D of a glass bulb body 2, 2' is set to 1.2-3, the local load onto the return part is lightened. Therefore, the temperature at the top T of the return part during the time when the lamp comes on is kept lower than the temperature in other parts. Therefore, the mercury in the bulb gathers onto the inner wall of the part T supposed to be the coldest part during the time when the lamp comes on, and the pressure of mercury in the bulb is determined according to the temperature at the part T. Therefore, in the lamp having the constitution proposed by the present invention, the mercury vapor pressure in the lamp can be kept at the optimum level.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement of a discharge lamp having a U-shaped discharge path.

In recent years, there has been a strong social demand for energy conservation.

Various new proposals have been made for various lighting equipment,
Efforts are being made to save energy.

Many attempts have also been made in the field of incandescent light bulbs, including attempts to downsize highly efficient fluorescent lamps to replace less efficient incandescent light bulbs.

One method for downsizing fluorescent lamps is to bend a conventional straight discharge tube into a U-shape to create a U-shaped discharge path, as shown in Figure 1. There are ways to shorten the length of the lamp.

This method of bending MJ1 into a U-shape makes it possible to easily reduce the length of the conventional long linear discharge tube by half or more, making it the most suitable method for making compact fluorescent lamps that can replace incandescent light bulbs. This is one method.

In addition, as a result of the research and development of the Zhongjin 6 phosphor, we have developed a high-load type IIK.
With the emergence of various phosphors that can withstand long periods of time and be used practically, efforts have been made to further reduce the size of phosphors.

However, in this U-shaped fluorescent lamp.

In order to reduce the size, a tube with a small diameter is used.

In order to set the overall length short and use it under high load conditions, the temperature of the lamp tends to rise, and as a result, the mercury vapor pressure inside the lamp rises beyond the optimum operating pressure. This had the disadvantage that the luminous efficiency was significantly reduced.

This invention aims at downsizing a fluorescent lamp by forming a U-shaped discharge path, and the ratio L/D of the diameter L) of the folded-back portion of the U-shaped discharge tube to the tube diameter Φ). By setting 1.2-IK stages, the coldest part is installed at the top of this folded part, and the mercury vapor pressure inside the lamp is controlled to the optimum operating range to achieve 6 luminous efficiency. The purpose of this is to prevent the decline.

FIG. 2 shows a small fluorescent lamp having a U-shaped discharge path, showing one embodiment of the present invention. In the figure, 11) indicates the entire lasip, 12+, (2') indicates the hyaline tube, and (
3) is a base to which a current introducing bottle is added, and an additional bottle is attached to the end of the glass tube (1!l, (2')).

Electrodes (not shown) are attached to the ends of the vitreous tubes (11, (2') on the base (3) side). (
4) connected the other end of the vitreous tube (21, (2')).

The folded part of the IJ-shaped discharge tube (c) is.

The top of this folded part is shown, (IJ is the length of the diameter of the folded part, (D) is the outer diameter of the vitreous tube body (21, (2')). 1. The inner walls are coated with phosphor,
A predetermined amount of mercury and rare gas are sealed inside.

I configured the above. When the small fluorescent lamp of this invention having a U-shaped discharge path is connected to a power source through a lighting device, it is installed and placed on the base of the glass tube (21, (2')). A discharge begins between the electrodes.

The current flows from (2) the upper electrode to the folded part of the discharge path (4)
, and flows in a U-shaped discharge path to the electrode (2') Ill.

Similar to a normal fluorescent lamp, the ultraviolet light generated by this discharge excites the phosphor coated on the inner wall of the tube, emitting visible light.

In the lamp of the invention shown in FIG.

The difference from the conventional lamp shown in FIG.
Since the ratio L/D of the diameter (D) of 2') is set to 1.2 to 3, the local load on this folded portion is reduced. As a result, when the lamp is on,
, (Temperature of Tl at the top of the 1'% reversing part is.

kept lower than other parts. Therefore.

While the lamp is lit, the mercury inside the tube becomes the coldest part c
'r> part mercury condenses on the inner wall, and the vapor pressure inside the lamp is determined by (1 part ii [K).

In the lamp having the configuration of the present invention, it is possible to maintain the mercury vapor pressure within the lamp at an optimum level, thereby improving the luminous efficiency of the lamp.On the other hand, in the conventional configuration shown in FIG. , a simple vitreous tube
It is bent into a U-shape to form a discharge path, and the diameter of the folded part (4) is the same as the diameter of the vitreous body.
Since the value of D L/D is 1, the temperature of the discharge tube rises while the lamp is on, making it difficult to maintain the mercury vapor pressure inside the tube at an optimum level. This significantly reduces the luminous efficiency of the lamp.

Table 1 shows one embodiment of the present invention in comparison with a conventional type.

In the conventional type shown in Table 1, a discharge path is formed by bending a 1-volume φ glass tube into a simple KU shape. The present invention is the same as the conventional type.
A glass tube with the same diameter of 13φ is used, one end is connected and molded, and the diameter of the folded portion is set to Ll of 20 wmK.

As is clear from Table 1, the beams have the same shape.

Comparing the dimensions of the lamp, the conventional efficiency is 4 T Jm/
v, whereas the efficiency of this invention is sI1m/W, which is an efficiency improvement of about 23%. Therefore, by applying the configuration of this invention, it is possible to achieve a significant efficiency improvement. It is possible.

In the above embodiment, the length of the diameter of the folded portion -i! L
The ratio L/D of the pipe diameter is 1-5 (L=20su*, D
= 13 m), but the value of this ratio L/D is 1.2 to 3
By setting it within the range of , the desired effect of the present invention can be obtained. If this value is less than 1.2.

The desired effect cannot be obtained, and even if the number exceeds 3, the effect does not increase any further.

In the above embodiment, the folded portion is the vitreous tube 12.
) and (2') are connected in a crosslinked manner, but the shape of the folded portion is not limited to this method.

Any material may be used as long as it enables formation of a U-shaped discharge path.

The folded portion may be formed by connecting two discharge tubes, or by forming the folded portion in advance with a mold.
It may be processed by any method.

In the above embodiment, a cylindrical glass tube was used as the discharge tube, but the i-discharge tube does not remain cylindrical, but has an elliptical shape, &! g
It may be of any shape, such as a polygonal tube such as a square tube.

In the above embodiment, this original discharge lamp is used.

Although the light was used as it is, it may be housed in a glass or plastic glove if necessary.

In the above embodiment, a glass tube with a diameter of 13 m was used, but the diameter is not limited to 13 m, and any diameter can be used as required.

As described above, the present invention is achieved by setting the ratio L/D of the folded portion diameter of the discharge tube forming the U-shaped discharge path (L) and the tube diameter (DI) to 1.2 to 3. Sh.

At the top of this folded part, a *1 cooling part is installed, which makes it possible to control the wood vapor pressure inside the lamp within the optimal operating range and obtain a small discharge lamp with high luminous efficiency. be.

[Brief explanation of the drawing]

FIG. 1 shows a conventional U-shape vibration lamp, and FIG. 2 shows an embodiment of the U-shape vibration lamp of the present invention. In the figure (1) is the entire lamp, +21. (2') is the hyaline tube body. (3) is the base, (4) is the folded part, (T) is the top of the folded part 11, (L) is the length of the diameter of the folded part, (middle) is the vitreous tube (2) (21 ) are shown respectively. In the drawings, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2

Claims (1)

[Claims] A discharge lamp characterized in that the ratio L/D of the diameter of the folded portion of the discharge tube forming a U-shaped discharge path to the diameter of the tube is 1.2 to 3.