JPH0452928Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a display tube for a light source that constitutes a pixel of a display device that displays an image by arranging a large number of display cells two-dimensionally. This invention relates to a getter mounting structure in a display tube.

[Conventional technology]

A conventional light source display tube will be described with reference to FIG. 3, taking as an example a one cell type light source display tube comprising 3.times.3 dot pixels.

This type of light source display tube has a general structure that is
As shown in the figure, a substrate 1 as a back plate and a side plate 2
A hermetically sealed vacuum container 4 is formed by the front panel 3 and the front panel 3, and the inner surface of the front panel 3 is coated with phosphors that emit light in red, green, and blue colors to form a 3×3 fluorescent dot. A surface 5 is formed.
Further, a common high voltage is applied to the fluorescent screens 5 in the vicinity of the inner surface of the front panel 3 including each of the fluorescent screens 5, and a frame-shaped accelerating anode electrode 6 is formed to surround each of the fluorescent screens. is front panel 3
A grid group 7 consisting of a plurality of grids is disposed perpendicularly to the anode electrode 6 and is disposed on the substrate side behind the anode electrode 6, corresponding to each of the phosphor screens 5.
is installed. A plurality of electron-emitting cathodes (filaments) 8 are disposed between the grid group 7 and the substrate 1, and are stretched between a pair of cathode supports 9 fixed on the substrate 1. Electrons emitted from grid group 7
The phosphor screen 5 is selectively controlled in each grid so that each phosphor screen 5 is irradiated uniformly. Also,
A getter 10 is attached to the pair of cathode supports 9, and by flashing the getter 10 by high-frequency induction heating or the like during assembly, the gas-adsorbing metal film, that is, the getter film 11, is attached to the side plate 2. This increases the degree of vacuum inside the vacuum container 4. In addition, in Figure 3, 1
Reference numeral 2 denotes each external lead terminal drawn out from the back side of the substrate 1.

In the light source display tube configured in this way, a high voltage of approximately 10 KV is applied to each of the fluorescent screens 5 and anode electrodes 6 of the front panel 3 via external lead terminals, and one selected from the grid group 7 is A voltage of several tens of volts relative to the potential of the cathode 8 is applied to each grid. Then, electrons emitted from the cathode 8 pass through the selected grid and are accelerated and irradiated toward the phosphor screen 5 corresponding to that grid, and this phosphor screen 5 is excited with a color corresponding to the phosphor. Emits light. Therefore, by selectively pulse-driving each of the grids in the grid group 7, any phosphor screen 5 can be excited to emit light by the electrons from the cathode 8 that have passed through these grids.

[Problem that the invention attempts to solve]

However, when the thermionic electrons emitted from the cathode 8 are accelerated with a high voltage as in the conventional light source display tube described above, most of the thermionic electrons enter the anode electrode 6 or the phosphor screen 5 to which a high voltage is applied. Although they contribute to making the phosphor emit light, some of the electrons enter the inner surface of the side plate 2. Since the electrons that entered the inner surface of this side plate 2 are accelerated by high voltage,
Causes secondary electron emission from the surface of the side plate 2,
As a result of emitting secondary electrons, its surface potential increases.
Here, the getter film 11 is a metal film formed by evaporating and scattering the metal (mainly Ba) filled in the getter 10 and depositing it on the inner surface of the side plate 2. The expansion of the area cannot be controlled due to variations in the distance between the side plate 2 and the side plate 2. Therefore, if the getter film 11 is kept at a low potential, when the distance between the getter film 11 and the part where the surface potential has increased becomes close, dielectric breakdown may occur at that part and creeping discharge may occur. In addition, since the cathode support 9 and the grid 7 are arranged close to each other, there is a possibility that an electrical touch may occur between the two electrodes due to the getter film 11.

The present invention was devised to solve the above-mentioned problems, and its purpose is to provide a display tube for a light source that has improved reliability by preventing electrical leakage and discharge due to the getter film. .

[Means for solving problems]

The display tube for a light source according to the present invention includes a vacuum container that is hermetically sealed by a rear substrate, a cylindrical side plate, and a front panel, and a phosphor screen formed on the inner surface of the front panel, and a high voltage is applied to the phosphor screen. a frame-shaped anode fixed perpendicularly to the front panel to surround the phosphor screen; an electron-emitting cathode disposed on the rear substrate in correspondence with the phosphor screen; and a grid for controlling the emitted electrons. In the display tube for a light source, a getter is disposed in a notch provided in a part of the anode electrode facing the surface of the side plate, and a getter film formed by the getter is at the same potential as the anode electrode. It was designed so that it would be maintained.

[Effect]

In the light source display tube of the present invention, by attaching a getter to the anode electrode, the getter film is formed on the inner surface of the side plate on the anode electrode side, effectively preventing leakage and discharge due to the getter film. can do.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a schematic structural diagram of a light source display tube according to an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view thereof. In the light source display tube of this embodiment, a vacuum container 4 which is hermetically sealed is formed by a substrate 1, a side plate 2, and a front panel 3, and in the vicinity of each fluorescent screen 5 formed on the inner surface of the front panel 3, A frame-shaped anode electrode 6 is provided to apply a high voltage to these phosphor screens 5 and surround the phosphor screens, and a plurality of grid groups 7 are provided corresponding to each phosphor screen 5.
The arrangement of the cathode 8 and cathode 8 is similar to that of the conventional example shown in FIG.
As shown in FIG. 2, the getter 10 is integrally attached so as to extend from one anode electrode 6 to the adjacent anode electrode 6. As a result, the getter 10 is disposed between the anode electrodes 6 at a position facing the side plate 2. Then, by flashing this getter 10 in the same manner as in the conventional method and depositing a getter film 11 on the inner surface of the side plate 2 facing the getter 10, this getter film 11 can also be used as a part of the anode electrode 6. This is what I did. That is, the anode electrode 6 is in contact with the side plate 2, and the getter film 11 formed when the getter 10 is flashed adheres to the side plate 2 and also to the anode electrode 6 at the same time. become the same potential. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

According to the configuration of the above embodiment, the getter film 11 is formed on the side plate 2 on the anode electrode 6 side in the vacuum container 4.
Since the getter film 11 is formed apart from the grid group 7 on the substrate 1 side, the cathode support 9 by the getter film 11 can be maintained without deteriorating the original function of the getter film 11.
There is no electrical contact between the grid electrode 7 and the grid electrode 7.
Moreover, since the getter film 11 is held at a high voltage that is the same potential as the anode electrode 6, even if the surface potential of the side plate 2 increases, the high voltages become the same and the potential difference is small, causing creeping discharge due to dielectric breakdown. Never. Furthermore, there is no need for a space for attaching the getter 10 between the cathode support 9 and the surface of the side plate 2, unlike in the conventional case, and there are advantages such as the tube itself can be made smaller.

In addition, in the above-mentioned embodiment, the case of a light source display tube comprising 3×3 dot pixels was shown.
The present invention is not limited to this, but can be applied to all one-cell type light source display tubes that constitute an arbitrary number of pixels.

[Effect of idea]

As described above, according to the light source display tube of the present invention,
A simple configuration in which the getter is integrally attached to the portion facing the side plate of the anode electrode can prevent leakage and discharge due to the getter film, resulting in a compact and highly reliable light source display tube.

[Brief explanation of the drawing]

1 and 2 are a schematic structural diagram and a partially cutaway perspective view of a light source display tube according to an embodiment of the present invention, and FIG. 3 is a schematic structural diagram showing an example of a conventional light source display tube. be. 1... Board, 2... Side plate, 3... Front panel,
4... Vacuum vessel, 5... Fluorescent screen, 6... Anode electrode, 7... Grid group, 8... Cathode, 9...
Cathode support, 10... Getter, 11... Getter membrane.

Claims (1)

[Scope of utility model registration request] A high voltage is applied to a vacuum container hermetically sealed by a rear substrate, a cylindrical side plate, and a front panel, and a phosphor screen formed on the inner surface of the front panel, and the phosphor screen is perpendicular to the front panel in order to surround the phosphor screen. A light source display tube comprising a fixed frame-shaped anode electrode, an electron-emitting cathode disposed on the rear substrate in correspondence with the phosphor screen, and a grid for controlling the emitted electrons. A light source characterized in that a getter is disposed in a notch provided in a part of the anode electrode facing the surface of the side plate, and a getter film formed by the getter is maintained at the same potential as the anode electrode. display tube.