JPH0636354B2 - Light emitting electron tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light emitting electron tube which emits light to the outside of a tube by exciting a light emitting gas sealed inside the tube by collision of electrons.

BACKGROUND ART As a conventional technique, for example, Japanese Patent Laid-Open No. 57-130364
There is a lamp as disclosed in Japanese Patent Publication.

In such a lamp, the inside of the tube body 1 is not made into a complete vacuum as shown in FIG. By accelerating with and making the anode 3 into an electron-passing shape, most of the electrons collide with mercury vapor, which is an ultraviolet ray radiating gas, in the back space 4 ', excite mercury to cause ultraviolet ray emission, and this ultraviolet ray is emitted. It is applied to a phosphor (ultraviolet-excited type) applied to the inner surface of the tubular body 1 to perform desired visible light conversion. In the figure, 5 is a DC power supply.

By the way, in such a conventional example, it is necessary to remove the influence of the space charge inside the tubular body 1 in order to make the electrons enter the back space 4 '. Therefore, it is necessary to apply a potential higher than the ionization voltage of the enclosed substance to the anode so that the inside of the tube body 1 is in a plasma state, and as a result, the electron energy in the back space 4'is considerably large as shown by the curve B in FIG. It is high and deviates greatly from the optimum value for excited light emission (curve A in FIG. 6), and there is a problem that the light emission efficiency is very poor.

[Object of the Invention] The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to reduce the energy of electrons in a tubular body,
Another object is to provide a light emitting electron tube with higher luminous efficiency.

DISCLOSURE OF THE INVENTION According to the present invention, a low-pressure light emitting gas is sealed inside, an annular tube body that is transparent to light radiation and has both ends communicating with each other, and a thermoelectron disposed inside the tube body. In a light emitting electron tube comprising an emission type cathode and an anode arranged inside the tube at a distance from the cathode which is equal to or less than the mean free path of electrons, the central through hole is surrounded by the tube. A magnet having N and S magnetic poles arranged in the diametrical direction is arranged, and the anode and the cathode are arranged so that the line connecting the anode and the cathode is orthogonal to the magnetic force line generated from the magnet. It is a thing.

The present invention will be described below with reference to examples.

Example 1 FIGS. 1 (a) and (b) show a schematic configuration of an example, in which a light-emitting gas such as mercury, cesium, sodium or the like is emitted at a low pressure in an annular tube body 1 having a light-transmitting property. The magnet 6 made of a permanent magnet is enclosed in the central through hole 7 surrounded by the tube body 1.
The N and S magnetic poles at both ends are positioned in the diameter direction of the central light transmission 7, and the generated magnetic force lines are arranged along the circumferential shape of the tubular body 1. Further, a thermionic emission type cathode 2 is provided inside the tube body 1, and the distance from the cathode 2 is equal to or less than the mean free path of electrons so as to obtain a positive characteristic discharge, and the cathode 2 is connected. The anode 3 is arranged so that the lines are orthogonal to the lines of magnetic force generated by the magnet 6.

Next, the operation of the light emitting electron tube of the present invention will be described based on the principle diagram of FIG.

First, when the voltage of the DC power supply 5 is applied between the cathode 2 and the anode 3, the electrons that have flown out of the cathode 2 enter the light emitting space 4 while being wrapped around the magnetic field lines (shown by the broken line in FIG. 2) of the magnet 6 and are sealed therein. It collides with a light emitting gas, such as Hg atoms, and changes its orbit. In other words, move to another magnetic field line. Then, the electrons are accelerated by the electric field and collide with Hg atoms again. By repeating this movement many times, the light emitting space 4 emits light uniformly over the entire surface. Here, the energy of electrons when they collide with Hg atoms will be described. First, FIG. 3 shows the potential distribution between the anode 3 and the cathode 2. From this figure, the energy obtained until the first collision of the electron jumping out of the cathode 2 is represented by ∫lEdl.

Here, the electron is the cathode 2 → l ₁ → l ₂ → as shown in Fig. 3.
Assuming that the route is l ₃ → l ₄ → anode 3,
The energy obtained in this process is ∫lEdl + ∫l
Edl + ∫lEdl + ∫lEdl = eVa. From this, the energy obtained until the electrons collide is considerably lower than the potential applied to the anode 3. Va is the anode potential,
E is the strength of the electric field. That is, the energy of the electrons in the space to emit light is considerably lower than the potential applied to the anode 3, which is suitable for exciting, for example, ultraviolet rays, and the light emission efficiency is further increased.

Example 2 In this example, a permanent magnet was used as the magnet 6 in Example 1 above, but as shown in FIG. 5, an electromagnet was used as the magnet 6 in this example.

In each of the embodiments, an annular tubular body having a short axial length is used as the tubular body 1, but it goes without saying that an annular tubular body having a relatively long axial length may be used.

EFFECTS OF THE INVENTION The present invention provides a light emitting electron tube configured as described above,
A magnet having N and S magnetic poles positioned in the diameter direction of the central through hole is arranged in the central through hole surrounded by the tubular body, and a line connecting the anode and the cathode is orthogonal to a magnetic force line generated from the magnet. Since the anode and the cathode are arranged so that the energy of the electron in the space to emit light is much lower than the potential applied to the anode, it is suitable for excitation. There is an effect that the rate of excitation by the γ is increased, the luminous efficiency is increased, and moreover, the annular luminescent space can be made to uniformly emit light by the above-described swirling motion of the electrons.

[Brief description of drawings]

1 (a) and 1 (b) are a top view and a side sectional view showing a schematic configuration of a first embodiment of the present invention, FIG. 2 and FIG. 3 are explanatory diagrams of the same operating principle, and FIG. 5 is a schematic perspective view of Embodiment 2 of FIG.
FIG. 6 is a schematic configuration diagram of a conventional example, and FIG. 6 is an energy distribution explanatory diagram of the same as above. Reference numeral 1 is a tubular body, 2 is a cathode, 3 is a cathode, and 6 is a magnet.

Claims (1)

[Claims] 1. A low-pressure light-emitting gas is sealed inside, an annular tube having a light-transmitting property with respect to light radiation, a heat-releasing cathode disposed inside the tube, and a cathode from the cathode. In a light emitting electron tube consisting of an anode disposed inside the tube at a distance equal to or less than the mean free path of electrons, in a central through hole surrounded by the tube, N, S in the diameter direction of the central through hole A light emitting electron tube characterized in that a magnet having magnetic poles is arranged, and an anode and a cathode are arranged such that a line connecting the anode and the cathode is orthogonal to a line of magnetic force generated from the magnet.