JP3030794B2 - Fluorescent display tube and method of manufacturing the same - 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 used for displaying numbers, characters, graphs, and the like on calculators, audio equipment, home appliances, measuring instruments, and the like.

[0002]

2. Description of the Related Art FIG. 3 shows, for example, Japanese Patent Publication No. 55-27418.
FIG. 1 is a diagram for explaining a configuration of a fluorescent display tube disclosed in Japanese Patent Application Publication No. H10-133139. In FIG. 3, (a) shows a 426 alloy (Fe-Ni-) well-known as a glass sealing metal having a matching thermal expansion coefficient with an anode substrate and a cover glass constituting a vacuum vessel of a fluorescent display tube. (Cr alloy) or the like by chemical etching. The metal frame 30 includes a frame forming portion 31, a grid mesh attachment frame 32, a grid outside lead portion 33, a segment anode outside lead portion 34, and a filament. A cathode external lead-out portion 35 and the like are formed. The metal frame 30 is manufactured by removing unnecessary portions of one sheet of the special alloy by chemical etching.

FIG. 3B shows a grid frame 39 formed by removing unnecessary portions by chemical etching of a stainless steel plate or the like comprising a mesh portion 36 serving as a grid electrode, a connecting portion 37 and a frame portion 38. Is shown.

FIG. 3C shows an anode substrate 45 on which a conductive contact portion 42 of an anode lead wire, an insulating paste 43 and a phosphor light emitting anode portion 44 are formed on a soda glass plate 41 by thick film printing. .

FIG. 3D shows a grid frame 39 positioned and welded to the metal frame 30 described above, and then unnecessary portions of the connecting portion 37 and the frame portion 38 are cut and removed. A metal frame 30 to which a filament 46 is welded and fixed is sandwiched between the anode substrate 45 and a cover glass 47 made of soda glass.
Shows a completed fluorescent display tube assembled product 49 hermetically sealed.

The external lead-out leads of each electrode are a filament cathode external lead-out part 35 electrically connected to the filament 46 via a filament holding bracket, a grid external lead-out part 33 electrically connected to the grid mesh by welding, and an anode lead. Each of the segment anode external lead-out portions 34 electrically connected to the wire conductive contact portion 42 with the conductive paste 50 is led out through the low melting point glass 48 of the hermetically adhered portion.

Next, after cutting and removing an unnecessary portion of the lead portion led out of the tube of the completed fluorescent display tube assembly 49, the anode substrate 45 and the cover glass 4 are cut through an exhaust pipe (not shown).
The space formed by 7 is evacuated to obtain a fluorescent display tube.

A fluorescent display tube of this type is disclosed in
Japanese Patent Publication No. 5-26582 proposes a fluorescent display tube as shown in FIG. This fluorescent display tube is different from FIG. 3 in that the fluorescent display tube in FIG. 3 has a metal frame 30 formed by removing unnecessary portions from a single metal plate by chemical etching. As shown, the supporting encapsulating wire 51 and the encapsulating piece 52 which are the lead-out leads for hermetic adhesion through each electrode
Connecting part metal plate 5 between outer lead parts 53 and 54 and each lead
5a and 55b are connected and fixed to each other by welding to form the metal frame 30A. Others are in Figure 3
In the same manner as above, a completed fluorescent display tube is obtained.

FIG. 5 shows a fluorescent display tube of this type.
Is disclosed in Japanese Patent Publication No. 55-30645. The difference between FIG. 5 and FIGS. 3 and 4 is that the filament 46, the grid electrode 56, etc.
57b or the non-conductive adhesive 58 for the anode substrate 4
5, the external lead wires of each electrode are constituted by a lead portion 59, a terminal portion 60 and an insulating layer 61 formed by printing a thick film of an Ag paste and an insulating paste on the anode substrate 45, and a metal frame body. 30 is not required. In addition, 62a and 62b are filament holders.

[0010]

However, the above-mentioned conventional fluorescent display tube has the following problems. Since the fluorescent display tube shown in FIG. 3 is formed by removing unnecessary portions from a single metal plate by chemical etching, the unnecessary portions are larger than the remaining necessary portions, and the loss of material is increased. . In addition, since the material to be used matches the thermal expansion coefficient with glass, 426 is used as described above.
Requires expensive materials such as alloys. Further, the chemical etching apparatus is a special apparatus, has no agility in responding to a design change or the like, and requires pollution treatment of an etching waste liquid. Further, the outside of the lead wire is soldered to the electrical connection with the device using the fluorescent display tube.
Alloy 26 is a material having extremely poor solderability, and may cause various difficulties and troubles in the processing of the external terminals.

The fluorescent display tube shown in FIG. 4 has been made to solve the above-mentioned problem of the fluorescent display tube, and has lead-out leads 51 and 52 and lead leads 53 and 54 outside the tube.
And the connecting portion metal plates 55a and 55b of the respective leads are formed separately, and connected and fixed by welding.
Since the metal frame is formed, material loss due to chemical etching is reduced, and another problem is solved by using a metal having good solderability for the leads 53 and 54.

However, in the fluorescent display tube of FIG. 3, the operation of forming the metal frame 30 by welding and fixing the respective metal parts is extremely troublesome, and the fluorescent display tubes of FIGS. Is formed of a thin metal plate, the lead wire take-out position is restricted, and it may not be possible to satisfy various customer requests.Because the connecting portion of each lead wire is formed of a metal plate, After the filament is fixed by welding, the metal frame 30 warps due to the tension of the filament 46 as shown in FIG. 6, making it difficult to clamp the metal frame 30 between the anode substrate 45 and the cover glass 47. In some cases, a trouble such as breaking of the filament 46 may occur.

The fluorescent display tube shown in FIG. 5 solves a part of the problems of the fluorescent display tubes shown in FIGS. 3 and 4, and does not use a large amount of expensive metal 426 alloy, and requires complicated work. Since there is no chemical etching step that requires the above, and the lead-out leads are formed on the glass substrate by thick film printing, the leads can be taken out at any position.

However, since the welding and fixing operation of the filament 46 must be performed directly on the filament holders 62a and 62b which are conductively fixed on the anode substrate 45, it becomes difficult to mechanize the filament tensioning operation.
It must be done manually, leaving the problem of labor saving.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to enable the mechanization of the filament tensioning operation without using a large amount of expensive material 426 alloy. And an inexpensive fluorescent display tube.

[0016]

In order to achieve the above object, a fluorescent display tube according to the present invention comprises a grid and an external lead wire of an anode formed on an anode substrate by a thick film or a thin film, and a filament cathode. The external lead-out wire is formed by passing a round bar of 426 alloy having a flat portion corresponding to the hermetically sealed portion through the hermetically sealed portion provided between the anode substrate and the cover glass. It is electrically fixed to a metal part welded and fixed to a round bar of 426 alloy, is held in a vacuum space, and has an electrical connection with an external device by soldering a lead pin to a printed terminal formed on an anode substrate.

Further, in the manufacturing method, a metal frame is formed by welding and fixing two 426 alloys, which are lead-out leads of the filament cathode, to a connecting portion formed of a metal round bar. It is sandwiched between a substrate and a cover glass, and is hermetically sealed and fixed.

[0018]

According to the present invention, the positions of the external lead wires of the grid and anode electrodes can be arbitrarily selected, and the metal frame of 426 alloy, which is a chemically etched part and an expensive material, is not required. It is easy to assemble, electrical connection with external devices can be easily done by soldering, and mechanization of filament tensioning work and prevention of warping of completed metal frame body can significantly improve assembly workability. it can.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an exploded perspective view illustrating a configuration of a fluorescent display tube according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a metal frame. In these figures, the anode substrate 1
Are an insulating layer 3 formed by printing a thick film of an insulating paste on a soda glass plate 2; a conductive connection wiring and a terminal portion 4 formed by printing a thick film of an Ag paste or a thin film of Al;
And a light emitting anode 5 formed by printing a phosphor paste in a thick film.

Next, on the anode substrate 1, a grid frame body integrally connecting a plurality of mesh portions 6 formed by press forming so as to be separated from the light emitting anode 5 by a predetermined distance is positioned and mounted. After the conductive or non-conductive paste 7 is applied and baked and fixed, the connecting portion of the grid frame is cut and removed to form an anode substrate assembly 8.

Next, above the anode substrate assembly 8, 426 alloy round bars 11a and 11b and a metal round bar 1
2 and a Nesa contact part 13 are integrally formed, and a filament anchor 15a having a spring part for giving tension to the filament 14 and a filament holder 15b to which the other end of the filament 14 is welded and fixed, respectively, are welded and fixed to a metal frame. The body is formed.

In this case, the above-mentioned 4 for leading outside the cathode lead is used.
As the round bars 11a and 11b made of 26 alloy, the portions 11 'corresponding to the hermetically sealed portions are flattened by press working before being integrated with the metal round bar 12 and the Nesa contact portion 13. The formation of the flat portion 11 'in the hermetically sealed portions of the round bars 11a and 11b not only improves the hermetically sealed condition described later but also causes the anode substrate 1 or the cover glass assembly 24 to generate cracks in the sandwiched portions thereof. Can be prevented.

Next, the metal frame assembly 17 is formed by fixing the filament 14 and the getter 16 on the filament anchor 15a and the filament holder 15b by welding and a jig (not shown). ing.

Next, above the metal frame assembly 17,
A cover glass assembly 24 is formed by applying a low melting point sealing glass to a sealing portion of the spacer glass 22, which is composed of a transparent glass plate 21 made of soda glass, a spacer glass 22, and an exhaust pipe 23.

Each of the assemblies constructed as described above firstly
The metal frame assembly 17 was sandwiched between the anode substrate assembly 8 and the cover glass assembly 24, sandwiched by clips (not shown), and applied to the cover glass assembly 24 using a sealing furnace (not shown). The low melting point sealing glass is melted and fixed. In this case, the 426 alloy round bars 11a and 11b for externally leading out the cathode lead are melt-fixed at their flat portions 11 '. Thereafter, the 426 alloy round bars 11a and 11b for leading out the cathode lead outside are cut at predetermined locations outside the tube, and the metal round bar 12 is cut off from the metal frame to assemble a fluorescent display tube as a completed product.

Next, the inside of the tube is evacuated through the exhaust tube 23, and a clip pin (not shown) is attached to the terminal portion 4. After a predetermined process such as aging and inspection, a fluorescent display tube is completed.

According to such a configuration, the amount of use of the 426 alloy can be greatly reduced, the mechanization of the assembling process becomes easy, and the position for taking out the external terminal can be arbitrarily selected.

In the above-described embodiment, the material of the metal round bar 12 is not particularly mentioned, but a soft iron wire is used. This material is a component that is attached to the outside of the fluorescent display tube, and is a component that is separated and removed when the fluorescent display tube is completed.
If the 6 alloy round bars 11a and 11b can be fixed by welding, the other material properties are not restricted at all.

[0029]

As described above, according to the present invention,
The mounting position of the external lead wire of each electrode of the grid and the anode can be arbitrarily selected, and does not require a metal frame of 426 alloy, which is a chemically etched part and an expensive material, and the metal frame is easy to assemble. The electrical connection with external devices can be easily made by soldering, and the mechanization of the filament tensioning work and the prevention of warping of the completed metal frame can significantly improve the assembling workability. An extremely excellent effect of being able to provide a fluorescent display tube capable of satisfying the various requirements described above is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a fluorescent display tube according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the metal frame shown in FIG.

FIG. 3 is a diagram illustrating a configuration of a conventional fluorescent display tube.

FIG. 4 is a diagram illustrating a configuration of a conventional fluorescent display tube.

FIG. 5 is a diagram illustrating a configuration of a conventional fluorescent display tube.

FIG. 6 is a diagram illustrating a problem of a conventional fluorescent display tube.

[Explanation of symbols]

 Reference Signs List 1 anode substrate 2 soda glass plate 3 insulating layer 4 terminal portion 5 light emitting anode 6 mesh portion 7 non-conductive paste 8 anode substrate assembly 11a 426 alloy round bar 11b 426 alloy round bar 11 'flat portion 12 metal round bar 13 Nesa contact part 14 Filament 15a Filament anchor 15b Filament anchor 16 Getter 17 Metal frame assembly 21 Transparent glass plate 22 Spacer glass 23 Exhaust pipe 24 Cover glass assembly

Continuation of front page (56) References JP-A-49-69071 (JP, A) JP-A-49-69070 (JP, A) JP-A-59-112533 (JP, A) JP-A-63-202820 (JP) JP-A-5-190125 (JP, A) JP-A-53-166379 (JP, U) JP-A-4-74844 (JP, U) JP-A-61-60456 (JP, U) JP-A 52-23160 (JP, U) JP-A 63-146960 (JP, U) JP-A 4-68356 (JP, U) JP-A 5-11297 (JP, U) JP-B 55-26582 (JP, U) B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 31/12-31/15 H01J 9/24 H01J 29/90

Claims (2)

(57) [Claims] 1. An anode substrate on which a wiring layer and a phosphor light emitting layer are formed by a thick film or a thin film, a mesh grid electrically conductively fixed on the anode substrate, and a plurality of grids arranged above the grid. A fluorescent lamp comprising a filamentary cathode, and a cover glass covering the grid and the cathode and hermetically sealed to the anode substrate, wherein a hermetically sealed space formed by the anode substrate and the cover glass is evacuated to a vacuum. In the display tube, the phosphor light-emitting layer and a lead wire externally extending from a grid are formed of a thick film or a thin film on an anode substrate surface, and the cathode is electrically connected to a metal part welded and fixed to a metal round bar.
Fixed and held in a vacuum space, the metal round bar is between the anode substrate and the cover glass.
Is disposed through the hermetic attachment portion provided in the
A fluorescent display tube characterized in that a portion that comes into contact with a hermetically sealed portion is formed flat . 2. An anode substrate on which a wiring layer and a phosphor light-emitting layer are formed by a thick film or a thin film; a mesh grid conductively fixed on the anode substrate; and a plurality of grids arranged above the grid. A fluorescent lamp comprising a filamentary cathode, and a cover glass covering the grid and the cathode and hermetically sealed to the anode substrate, wherein a hermetically sealed space formed by the anode substrate and the cover glass is evacuated to a vacuum. In the display tube, a step of forming the anode substrate, a step of conductively fixing a grid on the anode substrate, and two metal circles for leading out the outside of the cathode, the portions corresponding to the hermetically sealed portions being flattened. A step of welding and fixing two metal round bars to both ends of the rod to form a square frame; and a metal holding a filament in a vacuum space at a predetermined position of the two metal round bars for external lead-out of the cathode. A step of welding and fixing the component, a step of welding and fixing the filament to the metal component, and a step of sandwiching the frame to which the filament is fixed by welding between an anode substrate and a cover glass to hermetically seal the component, A step of cutting a predetermined portion outside the hermetic attachment of the two metal round bars for external derivation of the cathode to separate the two metal round bars from a frame, and a step of evacuating the inside of the hermetic attachment; A method for manufacturing a fluorescent display tube, comprising: