JPS61220268A - Light emission electron tube - Google Patents

Abstract

PURPOSE:To prevent droppage of light emission efficiency and accumulated ionization by integrating the cathode, the anode and the grid thereby facilitating to maintain constant the interval. CONSTITUTION:A doughnut type first insulator 10a is fixed to the opposite ends of a thermionic emission cathode rod 2 then a tubular meshed anode 3 for passing electrons is secured to the outercircumference. While a doughnut type insulator 10b is fixed to the opposite ends of anode and a tubular meshed grid 7 is secured to the outercircumference. The distance betweean the cathode 2 and anode 3 is formed shorter than the average free stroke of electron. With such arrangement, the interval between cathode/anode or anode/grid can be maintained constant easily resulting in a light emission electron tube where droppage of light emission efficiency or accumulated ionization can be prevented.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a light-emitting electron tube that excites a light-emitting gas sealed inside the tube by bombardment with electrons and emits light outside the tube.

(Background Art) As a prior art, for example, there is a lamp as shown in Japanese Patent Application No. 59-142631.

As shown in FIG. 4, such a lamp does not create a complete vacuum inside the tube body 1, but rather has a mercury vapor of several mTorr, for example.
A low vacuum of about r is used, and a thermionic emission type cathode 2 is used.
The emitted electrons are accelerated by applying an electric field, and the anode 3 and the energy control grid 7
By creating a mesh-like or lattice-like structure, most of the electrons are allowed to pass through and collide with an ultraviolet emitting gas such as mercury vapor in the back space 4 to excite the mercury and cause ultraviolet radiation. It is applied to a phosphor (ultraviolet-excited type) coated on the inner surface of the lamp to perform the desired visible light conversion. In addition, 5°8 in the same figure is a DC power supply, 6.9
is resistance. Moreover, FIG. 5 is a perspective view showing an electrode portion, and the same reference numerals are given to the same components as those described above.

By the way, in this conventional technology, since the cathode 2, anode 3, and grid 7 are individually attached, it is impossible to uniformly shorten the cathode-anode distance L+ and the anode-grid distance L2 due to the construction method. Therefore, between cathode 2 and grid 7,
Electrons emitted from the cathode 2 cause collisions with Hg atoms. Therefore, the energy of the electrons entering the back space 4 is not uniform, which not only reduces the luminous efficiency but also sometimes causes problems such as cumulative ionization between the cathode 2 and the anode 3 (at this time, V- 1 characteristic is negative).

(Object of the Invention) The present invention was made to improve the above-mentioned drawbacks, and its purpose is to prevent a decrease in luminous efficiency and cumulative ionization by integrating the cathode, anode, and grid. To provide a light-emitting electron tube that can emit light.

(Disclosure of the Invention) The present invention provides a tube in which a low-pressure light emitting gas is sealed and is transparent to light radiation, a cathode disposed inside the tube, and a distance from the cathode. an electron-transmissive anode disposed at a position where is shorter than the mean free path of electrons;
A light-emitting electron tube comprising an energy control grid disposed outside the anode and having the same shape as the anode and allowing electrons to pass therethrough, characterized in that the cathode, anode, and grid are integrated.

FIG. 1 is a diagram schematically showing an electrode portion according to the present invention, and a tube body (not shown) configured similarly to that shown in the background art.
That is, it is placed inside a tube hermetically formed of a material, such as transparent glass, that is transparent to the desired light radiation (light radiation here includes ultraviolet radiation and infrared radiation). will be established. In the figure, 2 is a thermionic-emitting rod-shaped cathode, 3 is an electron-transmissive anode formed in a cylindrical shape concentric with the cathode 2, and 7 is an anode 3.
The electron-transmissive energy control grids, TOA, and IOB, which are formed in a concentric cylindrical shape on the outside of the . Note that the other configurations are the same as those of the conventional example, so explanations will be omitted.

FIG. 2 shows an embodiment of the electrode part according to the present invention. At both ends of the cathode 2, there are donut-shaped first insulators 10 for insulation and for maintaining a uniform distance between the cathode and the anode.
A is attached to the insulator 10a, and a cylindrical mesh-like anode 3 is fixed to the outer periphery of the insulator 10a. A donut-shaped second insulator 10b is attached to both ends of the anode 3 to maintain uniform insulation and an anode-to-grid distance, and a cylindrical mesh-like grid is attached to the outer periphery of the insulator 10b. 7 is fixed.

FIG. 3 shows a different embodiment of the electrode portion according to the present invention. In this embodiment, an insulating plate 11 has a cathode 2 and an anode 3.
By fixing the grid 7, the distance between the cathode and the anode and the distance between the anode and the grid are kept uniform.

(Effects of the Invention) As described above, the present invention includes a tube in which a low-pressure light emitting gas is sealed and is transparent to light radiation, a cathode disposed inside the tube, and a tube body that is transparent to light radiation. an electron-permeable anode disposed at a position where the distance from the cathode is shorter than the mean free path of electrons; and an electron-permeable energy control grid having the same shape as the anode and disposed outside the anode. In the light emitting electron tube consisting of
It becomes easy to maintain a uniform distance between the anodes and the distance between the anodes and the grid. Therefore, according to the invention:
It is possible to provide a light-emitting electron tube that can prevent reduction in luminous efficiency and cumulative ionization.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electrode portion according to the present invention, FIG. 2 is a partially cross-sectional perspective view showing one embodiment of the electrode portion according to the present invention, and FIG. 3 is a different embodiment of the electrode portion according to the present invention. FIG. 4 is a schematic diagram of a conventional example, and FIG. 5 is a perspective view of an electrode portion of a conventional example. 1... tube body, 2... cathode, 3... anode,
7...Grid.

Claims (1)

[Claims] (1) A tube in which a low-pressure light emitting gas is sealed and is transparent to light radiation, a cathode disposed inside the tube, and a distance from the cathode that is equal to the mean free path of electrons. In a light-emitting electron tube comprising an electron-transmissive anode disposed at a shorter position and an electron-transmissive energy control grid disposed outside the anode and having a similar shape to the anode, the cathode, A light emitting electron tube characterized by integrating an anode and a grid.