JP2901435B2 - Fluorescent display tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube, and more particularly to a fluorescent display tube which is evacuated from an exhaust hole, sealed with a sealing lid coated with low-melting glass, and evacuated in a vacuum vessel.

[0002]

2. Description of the Related Art As shown in FIGS. 3A and 3B, an exhaust hole 2 formed in an anode substrate 1 is provided on the inner surface of a vacuum vessel because a vacuum device exhausts gas inside the vacuum vessel. The surface of the hole 2 was covered with the filament support 3 and the metal frame of the grid 4 so as not to hinder exhaust. this is,
As described above, exhaust holes 2
If the surface is covered with the metal frame of the filament support 3 or the grid 4, the vacuum level is reduced and the function of the fluorescent display tube is deteriorated at an early stage or over time. The structure not covered by the metal frame of No. 4 was indispensable.

[0003]

Since the exhaust hole provided in the glass substrate of the anode substrate is drilled with a metal drill or the like, fine glass chips are interposed or cracks are generated on the surface and the side wall of the exhaust hole. I do. For this reason, fine chips are released by impact or vibration, and cracks progress due to a large amount of heat treatment in the manufacturing process, and glass chips are generated. If these debris enters the vacuum vessel during the production and adheres to the surface of the phosphor layer or the electrode, there is a problem that the display quality is deteriorated or the reliability is impaired when emitting light.

An object of the present invention is to provide a fluorescent display tube having high display quality and high reliability.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a glass substrate, an exhaust hole formed in the glass substrate, a phosphor layer formed on the glass substrate, and a stretched support over the phosphor layer. An anode substrate including a filament provided, a filament support for supporting and fixing the filament, a phosphor layer and a grid disposed between the filament, and a cover glass sealed to the anode substrate to form a vacuum container When,
In a fluorescent display tube having a sealing lid for evacuating the vacuum container and sealing the exhaust hole with low-melting glass, a part of one of the filament support and the grid corresponding to the exhaust hole. And forming a plurality of holes smaller than the diameter of the exhaust hole.

[0006]

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1A, 1B and 1C are a sectional view of a main part of a first embodiment of the present invention, a plan view thereof, and a partially enlarged plan view of an exhaust hole portion.

In the first embodiment, as shown in FIGS. 1A, 1B and 1C, an exhaust hole 2 provided in an anode substrate 1 is formed.
Is disposed so as to cover a part of the filament support 3a in close contact with the exhaust hole 2. A part of the filament support 3a corresponding to the exhaust hole 2 is provided with a plurality of holes smaller than the diameter of the exhaust hole 2 by etching, and serves as a filter for preventing glass chips and the like from entering the vacuum vessel. I have.

FIG. 2 is a sectional view of a main part of a second embodiment of the present invention, a plan view thereof, and a partially enlarged plan view of an exhaust hole.

In the second embodiment, as shown in FIGS. 2A, 2B and 2C, an exhaust hole 2 provided in an anode substrate 1 is formed.
Is arranged so as to cover a part of the grid 4 a in close contact with the exhaust hole 2. A part of the grid 4a corresponding to the exhaust hole 2 is provided with a plurality of holes smaller than the diameter of the exhaust hole 2 by etching, and serves as a filter for preventing glass chips and the like from entering the vacuum vessel.

The second embodiment is advantageous when the vent hole 2 is far from the filament support 3. This is because, in the first embodiment, since the filament support 3 supports the filament 8, the filament support 3 floats due to the tension state of the filament 8 and the exhaust hole 2
May not be completely adhered to each other, and there is a possibility that glass chips may enter the vacuum vessel.

In each of the two embodiments, a plurality of small holes provided in a part of the filament support or the grid corresponding to the exhaust holes 2 have a diameter of about 0.25 to 0.3 mm.

[0013]

As described above, according to the present invention, a part of one of the filament support and the grid is brought into close contact with the exhaust hole, and a plurality of holes smaller than the exhaust hole are provided in that part. Can be prevented from entering into the vacuum container. Further, since a small hole at a position corresponding to the exhaust hole is formed more easily than etching, there is an effect that an inexpensive fluorescent display tube with high display quality and high reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of the present invention, a plan view thereof, and a partially enlarged plan view of an exhaust hole portion.

FIG. 2 is a sectional view of a main part of a second embodiment of the present invention, a plan view thereof, and a partially enlarged plan view of an exhaust hole.

FIG. 3 is a sectional view of a main part of an example of a conventional fluorescent display tube and a plan view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode substrate 2 Exhaust hole 3, 3a Filament support 4, 4a Grid 5 Sealing lid 6 Phosphor layer 7 Silver paste 8 Filament 9 Cover glass

Claims (1)

(57) [Claims] 1. A glass substrate, an exhaust hole formed in the glass substrate, a phosphor layer formed on the glass substrate, a filament stretched over the phosphor layer at a distance, and supporting the filament. An anode substrate including a filament support to be fixed, a grid disposed between the phosphor layer and the filament, a cover glass sealed to the anode substrate to form a vacuum container, and applying a vacuum to the vacuum container. In a fluorescent display tube having a sealing lid for sealing the exhaust hole with low-melting glass, a diameter of the exhaust hole is formed in a part of one of the filament support and the grid corresponding to the exhaust hole. A fluorescent display tube having a plurality of smaller holes.