JPH0670899B2 - Light emitting electron tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a light emitting electron tube that emits light to the outside of a tube by exciting a light emitting gas sealed in the tube by collision with electrons.

(Background Art) In recent years, as shown in FIG. 3, a light emitting gas such as mercury vapor is enclosed in a tube body 1 which is transparent to light radiation, and a thermionic emission type cathode 2 and an electron passage. A lamp of a type in which a conductive anode 3 is provided, electrons are accelerated between the cathode 2 and the anode 3, and excited and emitted by collision between electrons and gas atoms in a space 4 behind the anode 3 (for example, (Kaisho 57-130364). According to this method,
The energy of the electrons passing through the anode 3 and entering the back space 4 can be controlled by the voltage applied between the cathode 2 and the anode 3. There is a possibility that a highly efficient lamp can be realized by controlling the energy of this electron to the energy optimum for the excitation and emission of the light-emitting gas.

However, in the above-mentioned conventional lamp, it is necessary to ionize a part of the light emitting gas in order to remove the space charge effect due to the electrons in the back space 4 of the anode 3, and therefore a high anode voltage is applied. There is. Therefore, most of the electrons in the tube are given much higher energy than the optimum energy for exciting the gas atom to emit light, and the number of electrons contributing to the exciting light emission is small,
This reduces the luminous efficiency.

(Object of the Invention) The present invention has been made in view of the above problems, and an object of the present invention is to provide a light emitting electron tube having high luminous efficiency by controlling electron energy to be lower.

DISCLOSURE OF THE INVENTION The present invention relates to a photo-emission electron tube comprising a thermionic emission type cathode and an electron-transmissive anode arranged in a light-transmissive tube filled with a light-emission gas. And a static magnetic field generation source on the line connecting the center of the anode ring and the cathode and on the side opposite to the side where the center of the anode ring is located with respect to the cathode,
The static magnetic field source narrows the electron beam into the anode ring and diverges it in the space behind the anode.

Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is a simplified configuration diagram showing a light emitting electron tube according to the present invention. A material having a light-transmitting property with respect to desired light radiation (the light radiation here includes ultraviolet radiation and infrared radiation), for example, , A tube body 1 formed of transparent glass in an airtight manner
A thermionic emission type cathode 2 is disposed in the inside of the cathode, and an electron-passing ring-shaped anode 3 is located at a position equal to or shorter than the mean free path of electrons from the cathode 2.
Is provided. In addition, a low-pressure light emitting gas that is excited by collision of electrons such as vaporized mercury and can emit light is enclosed in the tube body 1, and the inner surface of the tube body 1 is
Phosphors are applied as needed. A heating power source 5 is connected to both ends of the cathode 2, and a voltage source 6 between the anode 3 and the cathode 2 in which electrons have energy capable of sufficiently ionizing a sealed gas and causing excitation.
Are connected. A static magnetic field generating source 7 such as a permanent magnet is arranged on the line connecting the center of the anode ring and the cathode and on the side opposite to the side where the center of the anode ring exists with reference to the cathode. ing.

FIG. 2 shows the electric field distribution in the vicinity of the anode according to the above embodiment. Since the anode 3 has a ring shape, the potential is low near the center. The electrons emitted from the cathode 2 have energy determined by the electric field distribution when passing through the anode ring 3. Therefore, the energy of the electron beam can be further reduced by narrowing the electron beam into the anode ring 3 by the static magnetic field generation source 7. In addition, the magnetic field distribution is the anode ring 3
Since there is divergence behind, a uniform light emission can be obtained in the back space 4. Further, the electrons that have passed through the anode ring 3 proceed in a state of being wrapped around the magnetic field lines B (shown by the alternate long and short dash line in the figure), so that the probability of collision with gas atoms increases and the luminous efficiency also increases.

(Advantages of the Invention) As described above, the present invention has a tube body having a low pressure light emitting gas enclosed therein and having a light-transmitting property with respect to light radiation, and a thermionic emission type arranged in the tube body. And an electron-permeable anode disposed at a position whose distance from the cathode is equal to or shorter than the mean free path of electrons, and a light-emitting gas is at least excited and emitted between the cathode and the anode. In a photo-emission electron tube formed by applying a voltage sufficient to operate the anode, the anode is formed in a ring shape, and the center of the anode ring exists on the line connecting the center of the anode ring and the cathode and with the cathode as a reference. The static magnetic field generation source is arranged on the side opposite to the side, and the static magnetic field generation source narrows the electron beam into the anode ring and diverges it in the space behind the cathode. It has the effect of lowering the gee and further increasing the probability of collision between the light emitting gas and the electrons, thereby increasing the luminous efficiency of the lamp.

[Brief description of drawings]

FIG. 1 is a simplified configuration diagram showing an embodiment of the present invention, FIG. 2 is an electric field distribution diagram near the anode according to the above embodiment, and FIG. 3 is a simplified configuration diagram of a conventional example. 1 ... Tube, 2 ... Cathode, 3 ... Anode, 4 ...
Back space, 5,6 ... Voltage source, 7 ... Static magnetic field generation source.

Claims (1)

[Claims] 1. A low pressure light emitting gas is sealed inside, a tube having a light transmitting property for light radiation, a thermionic emission type cathode provided in the tube, and a cathode from the cathode. An electron-transmissive anode disposed at a distance equal to or shorter than the mean free path of electrons, and a voltage sufficient for at least excitation and emission of the light-emitting gas is applied between the cathode and the anode. In the light emission electron tube, the anode is formed in a ring shape, and on the line connecting the center of the anode ring and the cathode and on the side opposite to the side where the center of the anode ring exists with reference to the cathode. A photo-emission electron tube characterized in that a static magnetic field generation source is arranged, and the static magnetic field generation source narrows an electron beam into an anode ring to diverge it in a space behind the anode.