JPS6119050A - Light-emitting electron tube - Google Patents

Abstract

PURPOSE:To enable given degrees of excitation and emission to be constantly produced during lighting by preventing electrons passing through the anode from remaining around the envelope wall. CONSTITUTION:A thermion-radiating cathode 1 and a meshy anode 2 located in front of the cathode 1, are installed in an airtight spherical envelope 3 made of transparent glass. The envelope 3 is charged with a gas at low pressure which can emit excited light when electrons strike it. The inner surface of the envelope 3 is coated with a phosphor as necessary. A second anode 4 consisting of a rough meshy conductor is installed along the inner surface of the envelope 3. The first and the second anodes 2 and 4 are adjusted to have almost equal electric potentials by an external circuit. By thus installing the second anode 4 catching electrons near the envelope wall, it is possible to constantly produce a given degree of emission during lighting.

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 collision of electrons and emits light outside the tube.

[Background technology]

As a conventional technique, for example, the one disclosed in Japanese Patent Application Laid-open No. 130364/1983 is a good example.

An overview of such conventional technology is given below using mercury (Hg) as a metal vapor.
The case in which the package is enclosed will be explained with reference to FIGS. 1 and 2. First, an electron e with a certain initial velocity collides with an Hg atom, the Hg atom becomes an excited state Kg, emits a photon (energy µv), and returns to the original Hg atom. Here, if the mean free path of the electron is λ, then Ll<λ (where Ll is the distance between cathode 1 and anode 2) holds, and electron e is at cathode 1
Collision with Hg atoms does not occur between and anode 2, but when passing through anode 2, it always collides with Hg atoms at least once. In addition, the anode 2 has a rough mesh shape, and the number of stone electrons captured by the anode 2 is very small.

In the electron tube as shown in FIG. 1, electrons that have passed through the anode 2 adhere to the inner wall surface of the tube body 3, generating a space charge inside the tube (see FIG. 3). The electric field reduces the speed of the electron flux passing through the anode 2,
A phenomenon occurs in which the Hg atoms no longer have the energy μ necessary to excite them, and as a result, the space charge increases due to the decelerated electrons, making it increasingly difficult to cause the excitation of Hg atoms to emit light. occured.

[Purpose of the invention]

The present invention was made in view of the above problems, and its purpose is to prevent the generation of space charge electric fields within the tube by preventing electrons that have passed through the anode from remaining on or near the tube wall. The objective of the present invention is to provide a light-emitting electron tube that can constantly excite Hg atoms and cause them to emit light.

[Disclosure of the invention]

FIG. 4 is a conceptual diagram of a light-emitting electron tube according to the present invention, in which a material 1 that is transparent to desired light radiation (light radiation herein includes ultraviolet radiation and infrared radiation), for example, A thermionic emission type cathode 1 is disposed inside a substantially spherical tube body 3 that is airtightly formed of transparent glass.
A mesh-like anode 2 is disposed on the front surface of the tube body 3, and a light emitting gas at a level V) is sealed inside the tube body 3, and a phosphor is coated on the inner surface of the tube body 3 as required. . And tube body 3
A second anode 4 made of a built-in mesh-like conductor is disposed along the inner wall surface of the anode, and is set by an external circuit so that the anode 4 and the first anode 2 have approximately the same potential. . The second anode 4 may be constructed by coating the inner wall surface of the tubular body 3 with a transparent conductive film. The design is such that the relationship Ll<λ<Lm holds, where the distances between them are Ls and Ls, respectively.

FIG. 5 shows the potential distribution inside the electron tube according to the invention, and as is clear from comparison with FIG. 2, there is no influence of indoor charges at all.

By providing the second anode 4 that captures electrons near the tube wall in this manner, a more uniform potential distribution within the tube can be maintained. In other words, the electron flux accelerated by the first anode 2 and passing through the anode 2 collides with and excites the Hg atoms, and then
Since it is captured by the second anode 4, no space charge is formed, and the potential distribution inside the tube can be kept uniform.1 Constant light emission can always be obtained while the lamp is lit. It was revealed.

Note that the enclosed gas is a rare gas of several Torr or less,
Several millimeters to several tens of millimeters! J Torr mercury metal vapor is preferable, and if a phosphor is coated on the inner wall surface of the tube body 3, the visible light emission can be intensified.

〔Effect of the invention〕

As described above, the present invention provides a second anode having approximately the same potential as the first anode along the inner wall surface or the vicinity of the inner wall surface of the tube, thereby always producing a constant excitation 0 emission during one lighting operation. We were able to provide a light-emitting electron tube that can generate light.

[Brief explanation of drawings]

t$1 is a conceptual diagram of the conventional example, FIG. 2 is a conceptual diagram explaining the light emitting operation same as above, FIG. 3 is a potential distribution diagram in the tube according to the conventional example, FIG. 4 is a conceptual diagram of the present invention, and FIG. 5 is a conceptual diagram of the conventional example. The figure is an in-tube potential distribution diagram according to the present invention. 1... Cathode, 2... First positive, 3... Tube body, 4
...Second anode.

Claims (1)

[Claims] (1) A tube body with a low-pressure light emitting gas sealed inside and transparent to light radiation, a thermionic-emitting cathode disposed inside the tube body, and a distance from the cathode. a mesh-like first anode disposed at a position shorter than the mean free path of electrons, and a second anode disposed along or near the inner wall surface of the tube and having approximately the same potential as the first anode. A light-emitting electron tube consisting of two anodes.