JPH03236153A - Light emitting electron tube - Google Patents

Abstract

PURPOSE:To improve the efficiency of a light source system by arranging a pair of electrodes at the interval several cm or below in a shielding tube body sealed with several kinds of light emitting gasses, and applying the magnetic field not in parallel with the line connecting both electrodes. CONSTITUTION:A bulb 1 with the outer diameter phi50mm is used for a light emitting tube, neon with 3Torr as a light emitting gas and mercury vapor are sealed in the bulb 1, a light emitting electron tube coated with phosphors 4 on the inner face of the bulb 1 and having the rated current 600mA is used, and a permanent magnet 4 made of a ferrite magnet is arranged around a base 5 so that the magnetic field intensity near the center of both electrodes 2 becomes tens gausses. The lamp voltage can be increased by about 20%. This value 20% can be further improved by adjusting the type and pressure of the sealed gas and the intensity of the magnetic field not to affect the lamp life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light-emitting electron tube that emits light by exciting a light-emitting gas sealed inside the tube with accelerated electrons.

[Prior Art] As shown in FIG. 6, a conventional light-emitting electron tube of this type has a pair of electrodes 2 inside a bulb 1 filled with light-emitting gas.
It is known that the device is equipped with
145055), each electrode 2 has an emitter coated on its surface, and the distance between the picture electrodes 2°2 is several cm to several mm.
They are placed relatively close together. Further, the inner surface of the bulb 1 is coated with a phosphor 3.

Therefore, as shown in Figure 7, when a predetermined voltage is applied to the picture electrodes 2 and 2, the electrons emitted from the cathode electrode are accelerated toward the anode electrode, and the electron flow that passes through them emits light. Ionizes and excites the gas.

The light emitting gas to be sealed is a low-pressure gas that is a mixture of mercury vapor and rare gas.

[Problems to be Solved by the Invention] Fig. 7 shows a diagram explaining the principle of a conventional light-emitting electron tube. It collided with atom a of , changing its orbit and causing ionization and excitation as shown in e2. Since the lamp current is determined externally, its voltage is determined to satisfy the following relationship:

[Lamp voltage] × [Lamp current] - ([Light output] ± [IN sudden loss] + [Ionization loss 1 + [Diffusion loss])・
・・・・・・■ Formula Here, [light output] + [collision loss] +
[Ionization loss] ± [diffusion loss] is caused by collision. ■The items in parentheses in the equation depend on the type and pressure of the light emitting gas. Therefore, in order to change the lamp voltage, it is necessary to change the type or pressure of the light emitting gas. This has a significant impact on lamp life and lamp efficiency. They are generally in a trade-off relationship.

In this way, the light-emitting electron tube has a low lamp voltage in principle (depending on the type and pressure of the rare gas, for example, the neon number T
(15 to 20 V at IA), therefore, in order to increase the lamp input, the current had to be increased.1 For example, when the lamp voltage is 15 V, the lamp current is IA and the input is 15 W.
The output will be approximately 500 lumens. Therefore, considering a lamp with an output of 1000 lumens, a current of 2 A or more is required.

This is a serious problem for lamp electrode design from the viewpoint of lamp life, and is also a serious problem for lighting circuit design from the viewpoint of power factor, cost, and circuit efficiency.

One way to solve this problem is to use a lamp that has two light emitting parts within the same space, but this is difficult due to the construction method and leads to increased costs.

The present invention has been made in view of the above problems, and its purpose is to increase lamp input by increasing lamp voltage with a simple configuration, shorten lamp life, and increase cost. An object of the present invention is to provide a light-emitting electron tube that improves efficiency as a light source system without causing any problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a translucent tube filled with several types of light-emitting gases, and a tube several centimeters deep inside the tube.
In a photoelectron emission tube consisting of a pair of electrodes arranged with the following rrJ19I, means is provided for applying a magnetic field so as not to be parallel to the line connecting the picture electrodes.

In the invention as claimed in claim 2, the direction of the magnetic field is substantially perpendicular to the line connecting the picture electrodes, and in the invention as claimed in claim 3, the strength of the magnetic field is set on a plane that is approximately equidistant from the picture electrode. It is set as the maximum.

[According to the present invention, when the magnetic field M is applied from the front side of the paper toward the back side as shown in the principle diagram of the present invention (Fig. 1) corresponding to the conventional principle diagram of Fig. 7, the cathode The electron e, coming out of K, tries to bend in the direction shown in the figure with the force of [eXvXB]. Therefore, the distance that the electron e moves becomes longer than when there is no magnetic field. As a result, since the pressure of the light emitting gas to be enclosed does not change, the number of collisions with the light emitting gas a to be enclosed also increases. As the number of collisions increases,
■Items that depend on the collision shown in the formula ([light output] + [!
The ratio of [1-hitting loss] + [1-separating loss]) increases.

Since the lamp current is constant here, the lamp voltage increases. The issue here is efficiency. If the above items increase at the same rate, efficiency will decrease. However, this can be compensated for by slightly changing the rare gas pressure (to the extent that it does not affect the lifespan) because the collision loss rate can be reduced. The other two terms are more influenced by mercury vapor pressure than by the noble gas.

By applying a magnetic field and compensating the efficiency with rare gas pressure as described above, the lamp voltage can be increased without significantly changing the life and efficiency.

The direction of the magnetic field may be any direction as long as it is not parallel to the line connecting the picture electrodes, but the most efficient direction is almost perpendicular to the line connecting the picture electrodes as in the invention described in claim 2. Efficiency is improved if the field strength is greatest on a plane that is approximately equidistant from the picture electrode.

Furthermore, as a light-emitting electron tube to which a magnetic field is applied, Japanese Patent Application Laid-Open No. 62-1
No. 63252, JP-A-62-276747, JP-A-6
Although these light-emitting electron tubes are different from each other in that they are light-emitting electron tubes to which a magnetic field is applied, their usage conditions and purposes are completely different. In other words, these light-emitting electron tubes use a magnetic field to limit the acceleration energy of electrons before they collide with the enclosed gas, thereby increasing efficiency. Therefore, for this purpose, the mean free path of electrons needs to be longer than the distance between the cathode and the anode. Further, the pressure of the gas sealed inside had to be approximately 0.0 ITorr or less.

In contrast, in the present invention, the sealing pressure condition is several T.

``r'', and is characterized in that the lamp voltage is increased by applying a magnetic field to increase the number of collisions with the light emitting gas to be enclosed. No. 62-163252, JP-A-62-2
76747, JP-A No. 62-276744, etc., but it has a completely different purpose under completely different conditions, and its operating principle is also different.

In addition, for applying a magnetic field to a general low-pressure fluorescent lamp, Japanese Patent Laid-Open No. 58-102488 and Japanese Patent Laid-Open No. 58-1024
There is a method described in No. 89, but these are different from the present invention in discharge form and purpose other than applying a magnetic field.

[Example] The present invention will be explained below with reference to an example. FIG. 2(a) shows an example, in which the outer shape of the light emitting part is φ
A 50 mm bulb 1 is used, and a light emitting electron tube with a rated current of 600 mA is used, in which 3 Torr neon and mercury vapor are sealed as light emitting gases, and a phosphor 4 is coated on the inner surface of the pulp 1. A permanent magnet 4 made of a ferrite magnet is arranged around the base 5 so that the magnetic field strength near the center of the picture electrode 2 is several tens of Gauss.

As a result, the lamp voltage could be increased by about 20%. This value of 20% is achieved by adjusting the type of gas, pressure, and strength of the magnetic field so as not to affect the lamp life.
Of course, it can be further improved.

If a strong magnet such as neodymium is used as the permanent magnet 4, it can be attached inside the cap 5 as shown in FIG. 2(b).

Although the above embodiment uses the permanent magnet 5 to apply the magnetic field, it is also possible to apply the magnetic field using an electromagnet, and FIG. 3 shows an embodiment using this electromagnet. In this embodiment, the electromagnetic coil 6 is arranged between the picture electrodes 2 so that the direction of the generated magnetic field is perpendicular to the line connecting the picture electrodes 2. In this case, assuming that the magnetic field strength obtained from the electromagnetic coil 6 is an exciting current IA, the coil inner diameter is 5 mm, and the required magnetic flux density is several tens of Gauss, it can be approximately determined from the following equation.

H=NXI/D H: magnetic field strength, N: number of turns, ■=current, D=inner diameter of the coil From this equation, the number of turns N of the electromagnetic coil 6 is from a dozen turns to several tens of turns.

By the way, light-emitting electron tubes are in principle affected by mercury vapor pressure, so when lighting them with the base down, as shown in Figure 4(a), there is no problem because the coldest spot is formed at a distance from the light emitting part. However, when the lamp is turned on with the base up as shown in FIG. 4(b), the temperature of the coldest point portion increases, resulting in a problem that the luminous efficiency decreases. Therefore, if a chip 7 for controlling the coldest point is provided in the light emitting section as shown in FIG. 5, the problem can be solved.

In this case, when the base up is lit, chip 7 is at the bottom! Moreover, since it is away from the plasma, the temperature remains low. Therefore, by putting mercury there first, the mercury vapor pressure can be controlled.

[Effects of the Invention] The present invention provides a photoelectronic system comprising a translucent tube filled with several types of light-emitting gases, and a pair of electrodes disposed inside the tube with an interval of several centimeters or less. Since the radiation tube is equipped with means for applying a magnetic field so that it is not parallel to the line connecting the picture electrodes, the distance that the electrons emitted from the cathode electrode move due to the magnetic field can be increased. Therefore, the number of collisions between the enclosed light emitting gas and electrons can be increased, and as a result, the lamp voltage can be increased and the lamp input can be increased.This can increase the lamp current and the pressure of the light emitting gas. There is an effect that the efficiency of the light source system can be improved without shortening the lamp life as would be the case if the number of lamps is increased, and the structure is simplified and the cost does not increase.

In the invention set forth in claim 2, the direction of the magnetic field is substantially perpendicular to the line connecting the two electrodes, so that the magnetic field works more effectively, and in the invention set forth in claim 3, the strength of the magnetic field is Since it is maximized on a plane that is approximately equidistant from both electrodes, it can be made even more effective.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2(a) is a partially cutaway perspective view of one embodiment of the present invention, and Fig. 2(b) is a partially cutaway view of another embodiment of the present invention. FIG. 3 is a partially cutaway perspective view of another embodiment of the present invention, FIGS. 4(a) and (b)
5 is a perspective view of another embodiment of the present invention, FIG. 6 is a partially cutaway perspective view of the conventional example, and FIG.
The figure is an explanatory diagram of the same principle as above. 1 is a bulb, 2 is an electrode, 3 is a phosphor, 4 is a magnet, and 5 is a cap.

Claims (3)

[Claims] (1) In a photoelectron emission tube consisting of a translucent tube filled with several types of light-emitting gases and a pair of electrodes arranged with a distance of several centimeters or less inside the tube. A light-emitting electron tube characterized in that it is provided with means for applying a magnetic field so as not to be parallel to a line connecting both electrodes. (2) The light-emitting electron tube according to claim 1, wherein the direction of the magnetic field is substantially perpendicular to a line connecting the picture electrodes. (3) The light-emitting electron tube according to claim 1, wherein the strength of the magnetic field is maximum on a plane that is approximately equidistant from both electrodes.