JPS6228523B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a high-output fluorescent lamp called a so-called VHO lamp. [Background technology] In recent years, high-output fluorescent lamps have been developed that increase the luminous flux by flowing a large current without changing the size of the fluorescent lamp, but the large tube current tends to cause an excessive rise in the tube wall temperature. There are problems in that it causes a decrease in luminous flux and a short lifespan. Figure 2 shows the relationship between the lamp tube wall temperature and the mercury vapor pressure inside the tube.
It reaches its maximum at 40℃ or mercury vapor pressure of 6 mTorr,
The efficiency of a fluorescent lamp decreases whether the mercury vapor pressure inside the tube is higher or lower than this, and this vapor pressure is determined by the temperature of the coldest spot on the tube wall. Therefore, in high-output fluorescent lamps, in order to pass a large tube current, it is necessary to maintain the tube wall temperature at an optimum level, and as shown in Figure 1, a protrusion 5 with a diameter of 10 mm and a depth of 10 mm is conventionally installed in the center of the tube.
Since this protrusion cools more easily than other parts, a method has been proposed in which a suitable coldest point temperature can be obtained. [Object of the Invention] However, the above conventional method is easy to break because the protrusion 5 protrudes, is inconvenient to transport and store, is difficult to manufacture, and is restricted in use by requiring the protrusion to face downward. There were many problems. It is an object of the present invention to solve the above-mentioned problems and at the same time to improve the luminous flux of the lamp without reducing the lamp efficiency. [Disclosure of the Invention] FIG. 3 shows an embodiment of the device of the present invention.
A straight tube type fluorescent lamp 1, in which a mixed gas of neon, argon, and krypton is sealed together with mercury particles in the tube, has the same polarity in the thickness direction over the entire length of the tube wall, excluding the small part 3 in the center of the tube and the electrodes at both ends. It is made by fixing magnetized strip-shaped permanent magnet pieces 2. In the embodiment shown in FIG. 4, a permanent magnet piece 2 magnetized in the same manner is fixed to a device 4 with, for example, the north pole facing upward. Next, the operating principle of the device of the present invention will be explained. Generally, when the atomic weight of the rare gas enclosed in a fluorescent lamp decreases, the temperature of the tube wall increases. On the other hand, as shown in Figure 5, when looking at the relationship between positive column power consumption and light output, the saturation level of light output increases as the atomic weight of the rare gas decreases, and when the positive column input is greater than 100W, neon gas-filled lamps produces more light than an argon gas-filled lamp. Therefore, high-output fluorescent lamps are often filled with a rare gas such as neon, which has a small atomic weight. However, when a rare gas with a small atomic weight is filled, the cathode drop voltage increases and electrode spatter is promoted, and the electron emissivity of the cathode decreases as the lighting time increases.As a result, the cathode drop becomes larger, resulting in cathode destruction. This has the disadvantage of shortening the life of the lamp. As a countermeasure to this, by filling in a rare gas with a large atomic weight such as krypton or xenon together with neon gas, the cathode drop voltage can be lowered and the lamp life can be extended. This also reduces the elastic collision loss between the rare gas and electrons, which reduces the lamp power and lowers the tube wall temperature to about 40°C, maximizing the efficiency of ultraviolet light generation from excited mercury atoms. , the ratio of total luminous flux to lamp power increases. However, on the other hand, as the lamp power decreases, the absolute amount of total luminous flux decreases, which goes against the original purpose of the high-output fluorescent lamp. Therefore, as in the present invention, when a magnetic field that crosses the direction of the electric field inside the lamp is applied, the electrons are bent by the electromagnetic force and electron-ion recombination on the tube wall is promoted, so that the potential gradient of the part where the magnetic field is applied is Since the lamp current is the same over the entire length of the tube, the power consumption of the magnetic field application portion increases, and the total luminous flux increases. Therefore, although the temperature of the tube wall in the part to which the magnetic field is applied increases, the temperature of the tube wall in the part 3 at the center of the tube to which no magnetic field is applied does not rise, and this becomes the coldest point temperature and determines the mercury vapor pressure. The reason why electron-ion recombination takes place on the tube wall is that because there is no gas that creates negative ions inside a fluorescent lamp, there is no high-speed capture of electrons mediated by negative ions, and the electrons collide with the tube wall. This is because they become negatively charged, which attracts positive ions and recombination occurs. [Example] For example, by the arrangement shown in Fig. 4, a pipe length of 1500
A rare gas mixture of 50% neon and 50% krypton is filled at 2.2 mTorr in a lamp with a tube diameter of 35 mm, and the tube is magnetized with the same polarity in the thickness direction with an interval of 5 to 10 cm in the center part 3 of the tube. Two permanent magnets 2 are provided,
Figure 6 shows the results of measuring the temperature at the outer wall of the lamp tube closest to the magnet when a magnetic field of approximately 300 G (Gauss) was applied and when no magnetic field was applied. Further, a characteristic table comparing both of the above examples with the conventional example shown in FIG. 1 (argon 100% 2.5 mTorr) having the same dimensions and the protrusion 5 is shown below. Comparing the conventional example and the present invention, the lamp power has decreased by 4%, the total luminous flux has increased by 5%, and the lamp efficiency has increased by 9%.

[Table] It is clear that a fluorescent lamp with high efficiency and long life can be provided. [Effects of the Invention] As described above, the present invention is a simple method of arranging static magnetic field generating means close to almost the entire length of the tube wall of a fluorescent lamp filled with mercury and a rare gas, except for a small part at the center of the tube. This structure has the advantage of increasing the power consumption of the positive column to achieve high output, and even if the tube wall temperature rises, the mercury vapor pressure is optimal due to the temperature of the coldest point in the center of the tube. This has the advantage that lamp efficiency does not decrease.

[Brief explanation of the drawing]

FIG. 1 is a side view of the conventional example, FIG. 2 is a diagram explaining the principle of the same as above, FIG. 3 is a side view of one embodiment of the present invention, FIG. 4 is a side view of another embodiment of the same as above, and FIG. 6 and 6 are explanatory diagrams of the principle of the present invention. 1 is a lamp, 2 is a permanent magnet piece, 3 is a small part in the center of the tube, 4 is an instrument, and 5 is a protrusion.

Claims (1)

[Claims] 1. The direction of electric field within the fluorescent lamp is controlled by a static magnetic field generating means disposed close to the wall of the fluorescent lamp filled with mercury and a rare gas along almost the entire length of the tube except for a small part at the center of the tube. A high-output fluorescent lamp device that forms intersecting magnetic fields. 2. Claim 1, comprising a strip-shaped permanent magnet piece magnetized with the same polarity in the thickness direction over the entire length of the tube wall, excluding a small central part of the fluorescent lamp tube and the electrodes at both ends. High output fluorescent lighting equipment.