JPH0685315B2 - 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, there is a lamp disclosed in, for example, JP-A-57-130364.

In such a lamp, the inside of the tube body 1 is not completely vacuumed as shown in FIG. 4, but a low vacuum in which mercury vapor exists for several mToor is used, and electrons emitted from the thermionic emission type cathode 2 are converted into an electric field. By accelerating with and making the anode 3 into an electron-passing shape, most of the electrons are in the back space.
At 4 ', it collides with mercury vapor, which is an ultraviolet radiation gas, to excite mercury to generate ultraviolet radiation, and this ultraviolet light is applied to the phosphor (ultraviolet excitation type) that is applied to the inner surface of the tube 1, and the desired visible light conversion is performed. Is to be done. 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 tube 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 as shown by the curve (b) in FIG. The value is high and deviates greatly from the optimum value for excited light emission (a curve in FIG. 5), and there is a problem that the luminous efficiency is very poor. Further, in the above configuration, since the light emitting region is fixedly set, there is a problem that the degree of freedom of light distribution is low because the light distribution must be controlled on the side of the appliance when the radiated light flux is used.

[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 of the present invention is to provide a photo-emission electron tube having a higher luminous efficiency and a variable degree of light emission in the tube to enhance the degree of freedom of light distribution.

DISCLOSURE OF THE INVENTION The present invention has a thermionic emission type cathode inside a spherical tube having a light emitting gas sealed therein and having a property of transmitting light to the light emission, and an anode having a hollow inside, The cathode and the anode are respectively arranged so that the distance from the cathode is equal to or less than the electron mean free path and the distance between the anode and the tube wall is sufficiently larger than the above electron mean free path, and near the tube wall near the cathode. Another static magnetic field generation source for varying the light emitting region, which is provided with a static magnetic field generation source and changes the relative position to the static magnetic field generation source to change the magnetic field formed in the tubular body with the static magnetic field generation source. Is provided near the tube wall at a site different from the static magnetic field generation source.

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

Example FIG. 1 shows a schematic configuration of an example. The tube body 1 has a light-transmitting property and is formed into a spherical shape, and contains mercury, cesium,
A light emitting gas such as sodium is enclosed, a thermoelectron emission type cathode 2 is disposed near the tube wall, and an annular anode 3 is disposed so as to face the cathode 2.
Further, a static magnetic field generation source 6 is arranged outside the tube wall in the vicinity of the cathode 2, and another static magnetic field generation source 6 for forming a magnetic field in the tube body 1 between the static magnetic field generation source 6 and the static magnetic field generation source 6 is provided. It is located in another position outside. Here, the distance from the cathode 2 located on a line orthogonal to the center of the closed plane of the anode 3 is L ′,
When the distance to the tube wall on the side opposite to the cathode 2 located on the line orthogonal to the center of the closed plane of the anode 3 is L and the average free path of electrons is λ, L ′ ≦ λ << L The respective arrangement relations are determined so that
That is, positive characteristic discharge is obtained.

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

First, a direct current voltage is applied between the cathode 2 and the anode 3, and the electrons jumping out of the cathode 2 are wrapped around the magnetic field lines (shown by broken lines in the figure) between the static magnetic field sources 6 and 6 and are the space behind the anode 3 in the light emission space. 4, and reciprocates along the lines of magnetic force until it collides with the enclosed light emitting gas. Therefore, the light emitting region can be freely changed by changing the positions of the static magnetic field generation sources 6 and 6 to change the lines of magnetic force.

Next, the energy possessed by electrons will be described with reference to FIG. 3. If, for example, the electrons jumping out of the cathode 2 pass through a locus 1 penetrating the closed plane of the annular anode 3, the energy becomes ∫leEdl. Where ∫lEdl <V
Since a (Va is the anode potential and E is the strength of the electric field), the energy of the electrons is lower than eVa. (Because the electron passes through the place where the potential is lower than Va.) As mentioned above, the energy obtained by the electron becomes much lower than the anode potential Va, and the energy becomes suitable for ultraviolet excitation, for example, and the rotation by the magnetic field line The movement increases the rate at which one electron is excited, resulting in an increase in luminous efficiency.
Furthermore, as described above, the distribution of the lines of magnetic force can be changed by changing the relative positions of the two static magnetic field generation sources 6, 6, and the light emitting region inside the tube 1 can be changed.

The static magnetic field generating source 6 may be a permanent magnet or an electromagnet including an exciting coil. Further, an appropriate phosphor may be applied to the inner peripheral surface of the tube wall, if necessary.

[Advantages of the Invention] The present invention has a thermionic emission type cathode inside a spherical tubular body which is transparent to light radiation and which has a hollow inside, and an anode and a cathode. The cathode and the anode are arranged such that the distance between the cathode and the anode is less than the electron mean free path and the distance between the anode and the tube wall is greater than the above electron mean free path, and the static magnetic field generation source is near the tube wall near the cathode. And a static magnetic field generation source for changing the light emitting region for changing the magnetic field formed in the tube between the static magnetic field generation source and the static magnetic field generation source by changing the relative position to the static magnetic field generation source. Since it was installed near the tube wall at a site different from the source, the energy obtained by the electrons was made considerably lower than the anode potential, and it was confirmed that one electron excites the light emitting gas by the swirling motion due to the magnetic field lines. The effect is that the rate can be increased.

In addition, since a static magnetic field source for varying the light emitting region is provided that changes the magnetic field formed in the tube by changing the relative position to the static magnetic field source provided near the cathode, There is an advantage that the light emitting region can be arbitrarily changed by arbitrarily changing the magnetic force line of. That is, in the present invention, since the tubular body is formed in a spherical shape, the electrons can be sufficiently long distance without disposing another static magnetic field source in the direction connecting the static magnetic field source provided near the cathode and the anode. Therefore, the probability of excitation of the light emitting gas can be increased without forming the magnetic field linearly, and as a result, the emission region can be changed while obtaining high emission efficiency. It will be possible. That is, when used as a light source, it is possible to control the light distribution independently without controlling the light distribution by a device such as a reflector provided separately, which is extremely useful in the industry that the degree of freedom of light distribution control is increased. It has an effect.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of Embodiment 1 of the present invention, FIG. 2, and FIG.
FIG. 4 is an explanatory diagram of the operation principle of the embodiment of the present invention, FIG. 4 is a schematic configuration diagram of a conventional example, and FIG. 5 is an explanatory diagram of the same as above. 1 is a tubular body, 2 is a cathode, 3 is an anode, and 6 is It is a source of static magnetic field.

Claims (1)

[Claims] 1. A thermoelectron emission type cathode and a hollow anode inside a spherical tubular body which is transparent to light radiation and which is filled with a light emitting gas, and the distance between the anode and the cathode. Is below the electron mean free path and the distance between the anode and the tube wall is larger than the above electron mean free path.The cathode and the anode are arranged respectively, and a static magnetic field generation source is provided near the tube wall near the cathode. Another static magnetic field generation source for varying the light emitting region, which changes the magnetic field formed in the tube between the static magnetic field generation source and the static magnetic field generation source, is used as the static magnetic field generation source. Is a light emitting electron tube, which is provided in the vicinity of the tube wall at a different portion.