JP2790073B2 - 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 having a getter inside an envelope, and more particularly to a getter holding structure.

[0002]

2. Description of the Related Art A fluorescent display tube 1 shown in FIG. 6 has an envelope 2 whose inside is in a high vacuum state. This envelope 2
Comprises an anode substrate 3, a front plate 4 facing the anode substrate 3,
This is a box-shaped container in which the anode substrate 3 and the side plate 5 provided between the outer peripheral edges of the inner surface of the front plate 4 are sealed with a sealing material. An anode 6 having a phosphor is provided on the inner surface of the anode substrate 3,
A control electrode 7 is provided thereon. On the inner surfaces of both ends of the anode substrate 3, a support member 8, which is a cathodic extending member, and an anchor member 9 having a spring property are provided by welding to a frame. The cathode 10 is stretched with a predetermined tension. On the inner surface of the front plate 4, a transparent conductive film 11 is formed so as to block the influence of an electric field outside the envelope 2 and to prevent charge of electrons. A contact lead 12 is formed integrally with one of the cathode extending members, for example, the anchor member 9, and is in contact with the Nesa film 11. Further, the getter shield 1 is provided on the support member 8 which is one of the cathode extending members.
3 are integrally formed, and a getter 14 is attached to a tip end thereof.

[0003]

As shown in FIG. 5, the support member 8 is a substantially strip-shaped member. Support member 8
A plurality of holding portions 8a are arranged side by side in the longitudinal direction to fix each one end of the plurality of filamentary cathodes 10 on one edge. On the other edge of the support member 8, an elongated getter shield 13 is provided extending in a direction orthogonal to the longitudinal direction. The support member 8 having such a configuration is integrally formed by progressively pressing a metal plate. Therefore, in order to take the plurality of support members 8 from one metal plate so as to be parallel to each other, the interval between the adjacent support members 8 must be large by the length of the getter shield 13. No. Accordingly, there is a problem that the number of support members 8 that can be formed from one metal plate is reduced, and there are many portions of the metal plate that are not effectively used.

The anchor member 9 is a substantially strip-shaped member. On one edge of the anchor member 9, a plurality of leaf spring-like arm portions 9 a are provided along the longitudinal direction to apply tension while holding one end of each of the plurality of filamentary cathodes 10.
Are juxtaposed. On the other side of the anchor member 9,
A contact lead 1 long in a direction intersecting the longitudinal direction
2 are provided. In order to obtain a plurality of anchor members 9 from one metal plate, the distance between the adjacent anchor members 9 must be increased by the length of the contact lead 12. Therefore, similarly to the support member 8, in the case of the anchor member 9, there is a problem that the number of the anchor members 9 that can be obtained from one metal plate is reduced, and there are many portions of the metal plate that are not effectively used.

Further, the getter shield 13 of the support member 8 and the contact lead 12 of the anchor member 9 have complicated shapes and must be formed into a predetermined shape by pressing after being formed from a metal plate by etching. However, there is a problem that it is complicated and difficult to automate.

An anchor member 9 made of a metal plate
The contact lead 12 has an elongated plate shape and has a tapered tip, so that it is almost in contact with the Nesa film 11 and there is a problem that the Nesa film 11 is broken when a high voltage is applied. .

Further, the getter shield 13 of the support member 8 is arranged on the opposite side of the holding portion 8a for holding the cathode 10, that is, inside the vicinity of the anode 6, and the getter 14 can be attached to the bent tip. There has been a problem that the interval between a certain anode 6 and the getter 14 becomes narrow, and the getter 14 narrows the viewing angle of display.

Further, the contact lead 12 of the anchor member 9 is connected to the anode 6 more than the arm 9 a holding the cathode 10.
The anode 6 which is a display part
The distance between the contact lead 12 and the contact lead 12 becomes narrow, and light from the anode 6 is reflected on the contact lead 12 to deteriorate display quality.

According to the present invention, a fluorescent display tube can be obtained in which a larger number of the cathode extending members can be obtained from a metal plate of a material, which has a simple structure, can be adapted to automation of production, has a reliable contact with a Nesa film, and has a high display quality. It is intended to provide.

[0010]

According to a first aspect of the present invention, there is provided a fluorescent display tube comprising: an envelope whose inside is maintained in a high vacuum state;
A cathode tension member provided on a first inner surface of the envelope;
A filament-shaped cathode stretched in the envelope via the cathode stretching member, and a display unit formed on the first inner surface;
In a fluorescent display tube having a conductive film formed on a second inner surface facing the first inner surface and a getter provided inside the envelope, a conductive post to which the getter is attached; And a support portion formed on the cathode tension member and supporting the conductive support.

According to a second aspect of the present invention, there is provided the fluorescent display tube according to the first aspect, wherein an end surface of the conductive support is in surface contact with the conductive film inside the envelope. And

[0012]

The conductive support to which the getter is attached is supported by the support of the cathode extending member, and makes surface contact with the conductive film formed on the inner surface of the envelope. Since the cathode extension member of the cathode is a simple shape without contact leads and getter shields,
The pitch at the time of removing the material from the plate material is reduced, the cost can be reduced, and the process can be simplified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The fluorescent display tube of this embodiment is different from the conventional one in the structure of the cathode extending member of the filament cathode 10. The configurations and functions of the envelope 2 having the transparent conductive film 11 on the inner surface, the filament-shaped cathode 10, the control electrode 7, the anode 6, and the like are substantially the same as those of the conventional fluorescent display tube described with reference to FIG. .

The getter 14 comprises a getter container 15 and a getter material 16 stored in the getter container 15. As shown in FIG. 1, the getter container 15 has a substantially annular shape having a round hole 17 penetrating at the center thereof, and has a peripheral groove 18 along the outer peripheral edge of the upper surface. The getter material 16 is stored in the circumferential groove 18. A conductive post 19 is press-fitted into a central round hole 17 of the getter container 15, and the getter container 15 is fixed to the conductive post 19. The conductive support 19 is made of 422 alloy (42%
Nickel, 2% chromium, balance iron), and its shape is cylindrical. The length of the conductive support 19 is set substantially equal to the distance between the anode substrate 3 and the front plate 4 constituting the envelope 2. In this embodiment, although the 422 alloy is used for the conductive support 19, 426 having a thermal expansion coefficient close to that of glass is used.
Alloys can also be used.

As shown in FIG. 2, in the fluorescent display tube according to the present embodiment, the support member 20, which is a cathode extending member of the cathode 10, is a substantially strip-shaped member. In order to fix one end of each of the plurality of filamentary cathodes 10 to one edge of the support member 20, a plurality of holding portions 2 are arranged along the longitudinal direction.
1 are juxtaposed. A support hole 22 for inserting and holding the conductive support 19 is arranged along the holding portion 21.
The support part 23 provided with is formed. Support part 23
Is slightly larger than the holding portion 21 of the cathode 10, but is considerably smaller than the elongated getter shield 13 in the support member 8 of the conventional fluorescent display tube. Accordingly, as shown in FIG. 2, when a plurality of support members 20 are integrally formed by progressively pressing a metal plate, the interval between the parallel support members 20, 20 does not need to be large as in the related art. . Therefore, the number of support members 20 that can be formed from one metal plate increases, and the metal plate can be used effectively.

As shown in FIG. 3, the support member 20
Each part is molded. In particular, the support portion 23 is formed so that the portion where the support hole 22 is formed is parallel to the anode substrate 3. The conductive support 19 is inserted into the support hole 22,
The support member 20 is set on the anode substrate 3 and the cathode 10 is stretched. In a state where the envelope 2 is constituted by the anode substrate 3, the front plate 4, and the side plate 5, the conductive support 19 is positioned between the anode substrate 3 and the front plate 4 in a direction perpendicular to the substrates 3, 4. It is clamped and fixed. The conductive support 19 is in surface contact with the transparent conductive film 11 formed on the inner surface of the front plate 4. The conductive support 19 has a cylindrical shape and is in contact with the transparent conductive film 11 at one end surface of a circular shape having a sufficient area, so that the electrical connection between the transparent conductive film 11 and the support member 20 is ensured.

As described above, in this embodiment, the conductive pillar 19 supporting the getter 14 also serves as a contact lead of the transparent conductive film 11. Therefore, although not shown, the anchor member of the present embodiment does not have the conventional contact lead. Therefore, when a plurality of anchor members are integrally formed by progressively pressing a metal plate,
The spacing between the parallel anchor members need not be as large as in the prior art. For this reason, the number of anchor members that can be obtained from one metal plate increases, and the metal plate can be used effectively.

Referring to FIG. 4, only portions of the second embodiment different from the first embodiment will be described. In this embodiment, the conductive support 1 is provided on a part of the outer peripheral surface of the disk-shaped getter container 25.
9 is fixed by welding. There is no hole in the center of the getter container 25. The configurations of the getter material 16 itself and the conductive support 19 itself are substantially the same as in the first embodiment. According to this embodiment, substantially the same effects as those of the first embodiment can be obtained.

[0019]

According to the fluorescent display tube of the present invention, the getter is attached to the conductive support, and the getter is held in the support formed on the cathode extending member, and is installed in the envelope. In contact with the conductive film. According to such a configuration, the cathode extension member of the cathode can be obtained from a larger number of metal plates of the material, so that the yield of the material is good and the manufacturing cost can be reduced. In addition, since the shape and structure of the cathode extending member are simplified, the manufacturing process is easily automated. In addition, since the conductive pillar and the Nesa film are securely in contact with each other on the surface, the withstand voltage is increased, and the risk of heat generation is small. In addition, since the conductive column holding the getter can be set apart from the anode, the display unit and the getter can be separated, and the viewing angle of the fluorescent display tube is widened. In addition, since the conductive column connecting the transparent conductive film and the cathode extending member can be set apart from the anode, light from the anode is not reflected on the conductive column and the display quality is not degraded.

[Brief description of the drawings]

FIG. 1 is a view showing a getter container and a conductive support in a first embodiment.

FIG. 2 is a view showing a state before forming an anchor member in the first embodiment.

FIG. 3 is a sectional view of the fluorescent display tube of the first embodiment.

FIG. 4 is a view showing a getter container and conductive posts in a second embodiment.

FIG. 5 is a view showing a state before molding of an anchor member in a conventional fluorescent display tube.

FIG. 6 is a sectional view of a conventional fluorescent display tube.

[Explanation of symbols]

 2 Enclosure 6 Anode 10 as Display Unit 10 Cathode 11 Transparent Conductive Film as Conductive Film 14, 24 Getter 19 Conductive Post 20 Support Member as Cathode Cathode Extension Member 23 Support

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshimichi Matsuda 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. (56) References JP-U 2-54150 (JP, U) (58) Fields surveyed (Int.Cl. ⁶ , DB name) H01J 29/94 H01J 31/15

Claims (2)

(57) [Claims] 1. An envelope whose inside is maintained in a high vacuum state,
A cathode tension member provided on a first inner surface of the envelope;
A filament-shaped cathode stretched in the envelope via the cathode stretching member, and a display unit formed on the first inner surface;
A fluorescent display tube having a conductive film formed on a second inner surface facing the first inner surface, and a getter provided inside the envelope; and a conductive post to which the getter is attached; A fluorescent display tube, comprising: a support portion formed on the cathode extending member and supporting the conductive support. 2. The fluorescent display tube according to claim 1, wherein an end face of the conductive support is in surface contact with the conductive film inside the envelope.