JPH11345582A - Negative electrode support and fluorescent character display tube using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contact with a glass adhesive and the generation of a fragment of the adhesive due to cracking by retaining an end of a filament- like negative electrode by one end of a negative electrode supporting member and arranging the other end on a lead plate located more inside than an edge of the lead plate. SOLUTION: A negative electrode support 1 is composed by welding a support 31 that is a negative electrode supporting member to a lead plate 2. A filament- like negative electrode 3 is welded to a holding part 33 of the support 31. A flat part 32 that is the other end of the negative electrode supporting member is so welded to the surface of the lead plate 2 located more inside than the edge of the lead plate 2 that the whole flat part 32 does not extend from the end of the lead plate 2. Time lead plate 2 is stuck to a glass substrate 10 through a glass adhesive 11. When the container of a fluorescent character display tube is sealed on the glass substrate 10 in a sealing process, the glass adhesive 11 is sintered, but not directly stuck to the negative electrode supporting member, so that no crack is developed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode support 1 for holding an end of a filament cathode 3 and transmitting a signal from an external input to the filament cathode 3, and a fluorescent display tube using the cathode support 1. In particular, the present invention relates to a fixing position between the cathode support 1 and the glass substrate 10.

[0002]

2. Description of the Related Art FIGS. 5A and 5B show an anchor 21 (movable end) as a cathode support member 20 and a support 31. FIG.
It is the said general | schematic perspective view of (fixed end). The anchor 21 and the support 31 are each a flat portion 2 to be welded to the lead plate 2.
Steps are provided between the flat portions 22, 32 and the holding portions 23, 33 in order to make the electrode parts three-dimensionally intersect with the holding portions 23, 33 to which the ends of the filament cathode 3 are welded. The connecting portions 26 and 36 are integrally formed in a step shape.

[0003] The holding parts 23 and 33 are composed of upper plate parts 24 and 34.
And lower plate portion 2 formed integrally with connecting portions 26 and 36
5, 35. Filament cathode 3
Is the upper plate 2 in the filament cathode welding process.
4 and 34 and the lower plate portions 25 and 35, while being sandwiched between the upper welding electrode and the lower welding electrode (not shown),
The support 31 and the holding portions 23 and 33 of the anchor 21 are welded respectively. Thereby, the filament cathode 3
Is stretched between the support 31 and the anchor 21.

The connecting portion of the anchor 21 needs to have an appropriate tension and stroke in order to stretch the filament cathode 3. Therefore, stainless steel, for example, SUS304 or the like is selected as the material of the anchor 21.
On the other hand, the material of the support 31 is 36% Ni, C
36 alloy consisting of 0.07%, 0.3% Si, 0.5% Mn, and the balance Fe.

As shown in FIG. 6 and FIG.
Is a cathode support member 20, specifically, its flat portions 22, 3
2 is welded to the lead plate 2. The lead plate 2 is connected to and integrated with the spacer frame 4.
In addition, a getter 8 and a grid or the like are attached to the spacer frame 4 as necessary. The one configured in this manner is called a mount 9.

On the other hand, the envelope of the fluorescent display tube is composed of a glass substrate 10 and a box-shaped container (not shown). An anode serving as a light emitting display section is formed on the glass substrate 10. A mount 9 is disposed on the glass substrate 10, and the back surface of the lead plate 2 and the surface of the glass substrate 10 are sealed with a base seal 11 made of a mixture of frit glass, a vehicle and an insulating paste.
To adhere.

Here, the material of the lead plate 2 is Ni of 42.
%, The alloy having a thermal expansion coefficient close to that of glass, such as a 42-6 alloy consisting of 6% Cr and the balance Fe. Therefore, the lead plate 2, the base seal 11, and the glass substrate 10
And the base seal 11 have strong adhesion, and the durability of the fluorescent display tube is improved.

Thereafter, in a sealing step, the container portion, the glass substrate 10 and the mount 9 are held in a state where the lead plate 2 is sandwiched between the sealing portion of the container portion and the outer peripheral edge of the surface of the glass substrate 10.
Is placed in a sealing furnace, and the container is sealed to the glass substrate 10.

However, in the sealing step, the base seal 11 printed on the surface of the glass substrate 10 protrudes in the width direction of the lead plate 2 as shown in FIG. . Since stainless steel, which is the material of the anchor 21, and alloy 36, which is the material of the support 31, both have different coefficients of thermal expansion from glass, distortion occurs near the boundary between the support 31 and the base seal 11 during cooling. When the rebase seal 11 cracks due to this distortion and fragments are scattered on the light emitting display surface, it causes light emission failure.

On the other hand, if the material of the cathode support member 20 is the same 42-6 alloy as that of the lead plate 2, the following problems occur. Although the cathode support member 20 needs to be formed thin,
It is difficult to work thin with 42-6 alloy. When the 42-6 alloy is used for the cathode support member 20, when the filament cathode 3 is stretched, the filament cathode 3 cannot be stretched due to plastic deformation. Therefore, stainless copper having spring properties is optimal. In the case of alloy 42-6, the weldability with the filament cathode 3 is poor. Stainless steel is chemically stable because it is difficult to adsorb the residual gas in the vacuum tube, and is preferable for the vacuum tube. Alloy 36 is cheaper than alloy 42-6 and is economically preferable.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to connect the other end of the cathode support member 20 to the edge of the lead plate 2 more. By providing on the lead plate 2 located inside,
The purpose of the present invention is to prevent generation of broken pieces of the glassy adhesive 11 due to contact with the glassy adhesive 11 and cracks. In this way, the light emitting surface is protected from the fragments of the glassy adhesive 11, and the light emission luminance and the life characteristics are improved.

[0012]

In short, the cathode support 1 according to the first aspect of the present invention is fixed on a glass substrate 10 with a glassy adhesive 11 and has a coefficient of thermal expansion substantially equal to that of glass. And a cathode support member 20 provided on the lead plate 2 and holding the filamentary cathode 3 and having a coefficient of thermal expansion different from that of glass. One ends 23 and 33 of the cathode support member 20 hold the ends of the filamentary cathode 3, and the other ends 22 and 32 of the cathode support member 20 are located inside the edge of the lead plate 2. It is provided on the lead plate 2.

According to a second aspect of the present invention, there is provided a fluorescent display tube including the cathode support according to the first aspect, wherein the fluorescent display tube is provided between the lead plate and the glass substrate. The extruded vitreous adhesive 11 and the other ends 22 and 32 of the cathode support member 20 are separated from each other, and the vitreous adhesive 11 and the other ends 22 and 32 of the cathode support member 20 are separated.
And a part of the lead plate 2 is interposed between them.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cathode support 1 according to the present invention and a fluorescent display tube using the cathode support 1 are shown in FIG.
This will be described with reference to FIG. In the following description,
The same reference numerals are used for the same or equivalent parts as those in the above-described conventional example, and the description is omitted.

FIG. 1 shows a cathode support 1 formed by welding a support 31 as a cathode support member 20 and a lead plate 2.
FIG. The flat portion 32, which is the other end of the cathode support member 20, is formed on the lead plate 2 located inside the edge of the lead plate 2, that is, so that the entire flat portion 32 does not protrude from the edge of the lead plate 2. Welded.

The lead plate 2 is a portion that is fixed to the glass substrate 10 via the glassy adhesive 11. For this reason, as the material of the lead plate 2, an alloy having a coefficient of thermal expansion close to that of glass is selected, such as a 42-6 alloy composed of 42% Ni, 6% Cr and the balance Fe.

The connecting portion 26 of the anchor 21 needs to have an appropriate tension and stroke to stretch the filament cathode 3. Therefore, stainless steel, for example, SUS304 is selected as the material of the anchor 21.
On the other hand, the material of the support 31 is 36% Ni, C
36 alloy consisting of 0.07%, 0.3% Si, 0.5% Mn, and the balance Fe.

FIG. 2 shows a filament cathode welding process on the support 31 side. Cathode support member 20
Is mounted on the stage 12. The holding portion 33, which is one end of the support 31,
It is composed of an upper plate part 34 and a lower plate part 35 formed integrally with the connecting part 36. The filament cathode 3 is
While being sandwiched between the upper plate portion 34 and the lower plate portion 35, it is welded to the holding portion 33 of the support 31 by being sandwiched between the upper welding electrode 13 and the lower welding electrode 14. Similarly, the other end of the filament cathode 3 is welded to the holding portion 23 of the anchor 21. Thereby, the filament cathode 3 is stretched between the support 31 and the anchor 21.

As shown in FIG. 3, the spacer frame 4 is formed in a frame shape by a pair of frame parts 5, 5 and a pair of lead plates 2, 2. The lead plate 2 is connected to and integrated with the spacer frame 4 with the external leads 6 for the cathode connected to both ends. Two sides of the spacer frame 4 that are integrated with the lead plate 2 face each other. A getter 8 is provided on the lead plate 2. Both ends of the frame portion 5 are connected to the cathode external lead 6, and the middle portion is connected to the anode external lead 7 and, if necessary, the control electrode external lead. When forming the control electrode, a grid is formed on the external lead for control electrode. The one configured in this manner is called a mount 9.

An anode having a phosphor is patterned in the middle of the glass substrate 10. Base seals 11 are applied to both ends. The base seal 11 is a glassy adhesive obtained by mixing powdery frit glass having a low softening point, a vehicle, and an insulating paste. The mount 9 is fixed on the glass substrate 10 with the base seal 11 interposed between the lead plate 2 and the glass substrate 10.

At this time, as shown in FIG. 4, the base seal 11 protrudes from the edge of the lead plate 2 and rises. The flat portions 22 and 32, which are the other ends of the cathode support member 20, are provided on the lead plate 2 located inside the edge of the lead plate 2. This interval is usually 0.5 mm to 1.5 mm. Therefore, the flat portions 22 and 32 and the base seal 11
Is separated from the protruding part.

Thereafter, in the sealing step, the mount 9 is sandwiched between the sealing portion of the box-shaped container constituting a part of the envelope of the fluorescent display tube and the outer peripheral edge of the glass substrate 10. The vessel is placed in a furnace and the container is sealed to the glass substrate 10. The sealing temperature is about 450 to 500 ° C. Each of the external leads 6 and 7 hermetically penetrates the sealed portion of the envelope and projects to the outside. At this time, although the base seal 11 is sintered, the base seal 11 is not directly fixed to the cathode support member 20, so that no crack occurs.

Then, the fluorescent display tube is taken out of the sealing furnace and is aged. Then, after aging, the gas inside the fluorescent display tube is exhausted to be airtight, and the frame portion 5 is cut off from the external leads 6 and 7. Thereby, a fluorescent display tube is manufactured.

[0023]

As described above, in the cathode support according to the present invention and the fluorescent display tube using the cathode support, the other end of the cathode support member is positioned inside the edge of the lead plate. With the provision of the above, it is possible to prevent contact with the glass adhesive and generation of fragments of the glass adhesive due to cracks. This also protects the light emitting surface from fragments of the glass adhesive, thereby improving the light emission luminance and life characteristics.

[Brief description of the drawings]

FIG. 1 is a side view of a cathode support according to the present invention.

FIG. 2 is a side view of a filament cathode welding process of a cathode support according to the present invention.

FIG. 3 is a plan view of a mount positioned on a glass substrate to manufacture a fluorescent display tube according to the present invention.

FIG. 4 is a side view when a cathode support according to the present invention is formed on a glass substrate.

FIG. 5 (a) is a schematic perspective view of a conventional anchor.
(B) It is a schematic perspective view of the conventional support.

FIG. 6 is a side view when a conventional cathode support is formed on a glass substrate.

FIG. 7 is a plan view of a mount positioned on a glass substrate for manufacturing a conventional fluorescent display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cathode support 2 ... Lead plate 2 ... Filament cathode 10 ... Glass substrate 11 ... Glass adhesive 20 ... Cathode support member (anchor 21, support 31) 23, 33 ... One end (holding part) 22 of cathode support member , 32 ... the other end (flat portion) of the cathode support member

Claims (2)

[Claims] 1. A lead plate fixed on a glass substrate with a vitreous adhesive and having a thermal expansion coefficient substantially equal to that of glass; and a lead plate provided on the lead plate, holding a filament cathode, and Cathode support members having different coefficients of thermal expansion,
In one embodiment, one end of the cathode support member holds an end of the filament cathode, and the other end of the cathode support member is located inside an edge of the lead plate. A cathode support provided on the lead plate located. 2. A fluorescent display tube comprising the cathode support according to claim 1, wherein the glass adhesive protruding from between the lead plate and the glass substrate, and The other end is separated, and a part of the lead plate is interposed between the vitreous adhesive and the other end of the cathode support member.