JPH025479Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorescent display tube, and more particularly to the structure of a fluorescent display tube for displaying characters, numbers, symbols, etc.

As shown in FIG. 1, a typical structure of a fluorescent display tube is that an anode substrate 2 on which a phosphor layer 1 forming a display pattern is formed and a cover glass 3 are sealed together, and a vacuum-tight container is formed. is formed. A filament 4 as an electron radiation source and an electronic control grid 5 are installed inside this vacuum sealed chamber, and each of these electrodes is electrically connected to the outside through lead terminals 6, 6', 6'', . . . Here, to explain the structure of the grid in detail, as shown in Fig. 2, the grid 5 is generally made of a thin conductive material with a thickness of about 0.05 mm, except for the outer periphery, and has a mesh structure by etching. It is bonded by welding to a thick frame-shaped conductor support part 7 (hereinafter referred to as a spacer) with a thickness of about 0.2 mm.

However, recently, the uses of fluorescent display tubes have expanded, and fluorescent display tubes for use in automobiles, etc. are required to have higher brightness than ever before, and along with this, it is necessary to increase the electronic input to the anode and grid. is occurring. At this time, the problem is that as the input to the grid increases, the grid heats up and becomes thermally deformed, which tends to cause problems such as display unevenness.This problem occurs at both ends of the grid in the filament direction. Easy to occur. This is because electrons from the filament part, which does not have a grid directly below, concentrate at the end of the grid.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a fluorescent display tube with improved display unevenness.

According to the present invention, an electrically controlled conductor section is installed adjacent to the thermally deformed part of the grid, and by dispersing the input of electrons into this conductor part, the electron input is concentrated on the deformed part of the grid. By preventing this and alleviating the thermal deformation of the grid, a fluorescent display tube with improved display unevenness can be obtained.

Hereinafter, the present invention will be specifically explained using the drawings. FIG. 3 is a cutaway perspective view showing an embodiment of the present invention. FIG. 4 is a schematic diagram showing the flow of electrons in the conventional structure, and FIG. 5 is a schematic diagram showing the flow of electrons in the embodiment of the present invention.

According to the present invention, a conductor section 8 is formed adjacent to the conventional grid section (hereinafter referred to as display section grid) 5 in FIG. 3, and is applied with a suitable positive potential. At this time, in the conventional structure, as can be seen from FIG. 4, electrons 10 are concentrated at the end 9 of the display grid, the temperature of the end 9 of the display grid increases, and thermal deformation is likely to occur.However, in the embodiment of the present invention, As can be seen from FIG. 5, since the electrons 10 are dispersed in the conductor portion 8, there is no concentration of electrons at the end portion 9 of the display grid, and thermal deformation of the end portion 9 of the display grid is significantly alleviated. FIG. 6 shows another embodiment of the present invention, in which the spacer of the display grid 5 is extended outward, and a conductor grid 8 having a mesh-like structure similar to the display grid 5 is welded onto it. are doing. In the embodiment shown in FIG. 6, electrons concentrate on the conductor grid 8, which tends to cause thermal deformation, but it is better to separate the conductor grid and the display grid and weld them to the spacer. Therefore, the influence of thermal deformation on the display grid is reduced.

[Brief explanation of the drawing]

FIG. 1 is a cutaway perspective view showing the structure of a generally known fluorescent display tube. FIG. 2 is a cutaway perspective view showing the general structure of the grid section. FIG. 3 is a cutaway perspective view showing one embodiment of the present invention. FIG. 4 is a schematic diagram showing the flow of electrons in a conventional structure. FIG. 5 is a schematic diagram showing the flow of electrons in an embodiment of the present invention. FIG. 6 is a cutaway perspective view showing another embodiment of the present invention. 1... Display portion phosphor layer, 2... Anode substrate, 3...
...Cover glass, 4...Filament, 5...Display grid, 6, 6', 6''...Lead terminal, 7
... Spacer, 8 ... Conductor section, 9 ... Display grid end (place where thermal deformation is likely to occur), 10 ...
...A schematic representation of the flow of electrons.

Claims (1)

[Scope of utility model registration request] In a fluorescent display tube that displays numbers and symbols by accelerating and controlling thermoelectrons emitted from a filament using a grid and impacting a phosphor layer formed on an anode segment, there is an electrically connected wire near the grid. A high brightness fluorescent display tube, characterized in that a controlled separate conductor section is formed spaced apart from the grid.