JPH0722450U - Fluorescent display tube - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a fluorescent display tube in which display by a getter mirror is not hindered. [Structure] The getter container 20 has an oval outer shape. The elliptical minor axis B is defined by the front plate 3 and the substrate 2 in the vacuum container 1.
Smaller than the interval. The getter container is attached to the base 7a of the cathode support 7 inside the vacuum container. The getter container is placed horizontally so that the direction of the minor axis B is aligned with the height direction of the vacuum container, and the opening on the upper surface of the getter container faces the inner surface of the side plate at a predetermined interval. Getter mirror 2
2 is formed on the inner surface of the side plate. This getter mirror does not affect the observation of the display unit 6 through the front plate at all.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluorescent display tube having a getter container inside a vacuum container.

[0002]

[Prior art]

 As shown in FIG. 4, a fluorescent display tube generally has a flat box-shaped vacuum container 1. The vacuum container 1 has a structure in which a substrate 2 and a translucent front plate 3 are sealed via a side plate 4. A display unit 6 having a phosphor 5 on the inner surface of a substrate 2 is provided inside the vacuum container 1, and a pair of cathode supports 7 is provided at both ends of the substrate 2 sandwiching the display unit 6. A filament cathode 8 is provided and stretches above the display unit 6.

As shown in FIGS. 4 and 5, inside the vacuum container 1, a getter container 9 is provided to maintain the degree of vacuum inside the vacuum container 1. The getter container 9 is an annular storage container having an open upper surface, and is filled with a getter material such as Ba inside. The getter container 9 is attached to the base portion 7a of the cathode support 7 via a mounting member 10 and faces the inner surface of the front plate 3 of the vacuum container 1 at a predetermined interval. When this getter container is heated from the outside of the vacuum container 1 with an electromagnetic induction heater (bomberter), the getter material is evaporated and vapor-deposited on the inner surface of the front plate 3 to form the getter mirror 11.

Although the size of the getter container depends on the internal volume thereof, conventionally, the getter container has a small outer diameter of about 3.5 mm or more. On the other hand, the distance between the front plate 3 and the substrate 2 inside the vacuum container 1 was, for example, about 2.6 mm, which was smaller than the outer diameter of the getter container. Therefore, the upper surface must be arranged close to the front plate 3 so as to be formed in the above. In this case, the distance between the getter container 9 and the front plate 3 was conventionally set to about 0.5 mm. In such a size setting, the getter mirror 11 formed on the inner surface of the front plate 3 usually has an outer diameter of about 8 to 10 mm.

[0005]

[Problems to be solved by the device]

 In fluorescent display tubes, the display pattern is becoming higher in density, and the display area is expanding toward the end of the vacuum container. For this reason, as shown in FIG. 4, the getter mirror 11 formed on the inner surface of the front plate 3 may be formed on the edge portion of the display unit 6 to hinder the display. There was a problem.

Further, if the distance between the getter container 9 and the front plate 3 is made smaller, the getter mirror 11 also becomes smaller. However, in order to maintain the degree of vacuum in the vacuum container 1, the getter mirror 11 is required to have an area of a certain extent or more, and therefore the interval cannot be reduced inevitably. If the gap is 0.5 mm or less, the getter container is more likely to come into contact with the front plate 3, and if it is in contact with the front plate 3, heat is transmitted to the front plate 3 at the time of high frequency heating and cracks occur in the front plate 3. Dangers arise.

An object of the present invention is to provide a fluorescent display tube in which the area of the getter mirror is appropriate, the degree of vacuum in the vacuum container can be maintained, and the display by the getter mirror is not hindered.

[0008]

[Means for Solving the Problems]

 The fluorescent display tube of the present invention is a fluorescent display tube in which a getter container is provided inside a vacuum container in which a substrate and a front plate are sealed by a side plate, and the getter container has outer dimensions of the substrate and the front plate. It is characterized in that a getter mirror is formed on the inner surface of the side plate, which is smaller than the distance between the face plates.

[0009]

[Action]

 Since the upper surface of the getter container, which is the direction of evaporation of the getter material, is directed toward the inner surface of the side plate of the vacuum container, a getter mirror can be formed on the inner surface of the side plate, and the display by the getter mirror is not obstructed.

[0010]

【Example】

 In each of the embodiments described below, the same parts as those in the prior art are designated by the same reference numerals as those in FIGS. 4 to 5 to simplify the description. The getter container 20 provided in the vacuum container of the fluorescent display tube of the present embodiment has an oval shape as shown in FIG. The minor axis B of the elliptical shape is set to be smaller than the distance between the front plate and the substrate in the vacuum container of a general fluorescent display tube. For example, if the distance is 2.6 mm, the minor axis B of this getter container is, for example, 2. Set to 2 mm or less. The major axis A has the same capacity as that of the conventional getter container, and the minor axis B is a dimension determined when the minor axis B is set to a certain dimension of 2.2 mm or less.

As shown in FIG. 2, the getter container 20 is attached to the base portion 7 a of the cathode support 7 in the vacuum container 1 of the fluorescent display tube via a mounting member 21. Here, in the getter container 20, the major axis A is parallel to the surfaces of the front plate 3 and the substrate 2, and the central axis of the getter container, which is an annular body, is perpendicular to the surface of the side plate 4. That is, the getter container 20 is placed horizontally so that the direction of the minor axis B is aligned with the height direction of the vacuum container so that the opening on the upper surface of the getter container 20 faces the inner surface of the side plate 4 at a predetermined interval. Attach in a proper posture.

Even if the inner height of the vacuum container 1 (the distance between the inner surface of the substrate 2 and the inner surface of the front plate 3) is 2.6 mm, the minor axis B of the getter container 20 of this embodiment is 2. Since the thickness is set to 2 mm or less, the getter container 20 can be placed horizontally as described above, and the getter mirror 22 can be formed on the inner surface of the side plate 4. Therefore, the getter mirror 22 does not affect the observation of the display unit 6 through the front plate 3 at all.

The getter container 20 has an elliptical shape so that it can be placed horizontally in the narrow vacuum container 1 as described above, but the capacity for accommodating the getter material is set so as not to be different from the conventional one. ing. Therefore, the thickness and area of the getter mirror 22 formed are guaranteed to be values sufficient to maintain the degree of vacuum in the vacuum container 1.

In the above-described first embodiment, one elliptical getter container 20 was used, and this getter container 20 was placed horizontally in the vacuum container 1. However, as shown in FIG. 3, it is conventionally used. It is also possible to use two circular getter containers 23, which are smaller than the circular getter containers, and arrange these so that they are placed horizontally and face the side plate 4. With such a structure, as in the first embodiment, the effect that the getter mirror 24 can be formed on the side plate 4 that does not affect the display can be obtained.

In addition, if a plurality of small getter containers 23 are arranged as described above, in addition to the above-described effect, the required size of the getter mirror differs depending on the size of the vacuum container. Since the number of getter containers provided in the vacuum container can be arbitrarily selected, there is an effect that the getter container can be a common component between different fluorescent display tubes having vacuum containers of different sizes.

It should be noted that the specific dimensions of each member described in each of the above-described embodiments are merely examples.

[0017]

[Effect of device]

 According to the fluorescent display tube of the present invention, the getter container has an outer dimension smaller than the distance between the substrate and the front plate, and the getter mirror is formed on the inner surface of the side plate, so that the display is not obstructed by the getter mirror. The effect is that the degree of vacuum in the vacuum container is also maintained.

[Brief description of drawings]

FIG. 1 is a view showing an outer shape of a getter container according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a fluorescent display tube according to a first embodiment of the present invention.

FIG. 3 is a plan view of a fluorescent display tube according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional fluorescent display tube.

FIG. 5 is a perspective view showing a conventional getter container and its mounting structure.

[Explanation of symbols]

 1 Vacuum Container 2 Substrate 3 Front Plate 4 Side Plate 20,23 Getter Container 22,24 Getter Mirror

Claims (3)

[Scope of utility model registration request] 1. In a fluorescent display tube in which a getter container is provided inside a vacuum container in which a substrate and a front plate are sealed via a side plate, an external dimension of the getter container is a distance between the substrate and the front plate. And a getter mirror formed on the inner surface of the side plate. 2. The getter container has an elliptical shape, and its minor axis is smaller than the distance between the substrate and the front plate.
The fluorescent display tube described. 3. A plurality of circular getter containers having a diameter smaller than the distance between the substrate and the front plate are provided.
The fluorescent display tube described.