JPH0426033A - Cathode structure erecting method for cathode ray display device of flat plate type - Google Patents

Abstract

PURPOSE:To prevent an electrod from oxidation by mounting cathode supporting terminal means not directly to a recess provided in the back plate, but through an assembly base made of metal. CONSTITUTION:A cathode-ray display device concerned is equipped with a plurality of wire cathodes 12 set stretched in parallel with one another, a control electrode 16 installed on a back plate 14 positioned in the direction intersecting the wire cathodes 12 at right angles, a deflecting electrode 20 which deflects electron beam into the direction perpendicular to the wire cathodes 12, and a fluorescent substance layer 24 which is installed on a facade plate 26 and with which an anode 22 is installed consolidatedly, wherein the back plate 14 is provided with a recess 32 between a frame 30 and a base 28 where the control electrode 16 is installed. An assembly base 42 made of metal is installed in this recess 32, and thereon cathode supporting terminal means 36, 38 are fixed by means of welding, and the wire cathodes 12 are set over them in tension. This eliminates exposure to the oxidative atmosphere resulting from baking of frit glass, and generation of cathode contamination and oxidation of electrode can be prevented.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a flat cathode ray tube display device for displaying characters and graphics. This invention relates to an improvement in a method for assembling a cathode structure of a cathode ray tube display device in which a single image is displayed on a screen by connecting rasters generated by deflection or the like.

(Prior Art) The present applicant has previously proposed a flat panel image display device using cathode rays. To explain the structure and operating principle of this display device, as shown in FIGS. 1 and 2, this display device includes a plurality of linear cathodes 12 arranged parallel to each other at a predetermined interval, A horizontal control electrode 16 is arranged on the back plate 14 and is provided perpendicular to the linear cathode 12.
, an electron extraction electrode 18 provided immediately before the cathode 12 and divided horizontally in substantially the same way as the cathode 12, a pair of vertical deflection electrodes 20 provided to sandwich the cathode 12, and a plurality of cathodes. The front plate 26 has a phosphor film 24 on which an anode 22 is metal-backed on an insulating substrate such as glass. In the drawing, adjacent deflection electrodes of the pair of vertical deflection electrodes 20 are fused together. Further, in FIG. 1, for clarity of explanation, only the electrodes of each part are shown, and parts such as the envelope and getter are omitted except for the front plate 26 and the back plate 14. In addition, in this specification, r horizontal direction 1
refers to the data input direction, and r perpendicular direction 1 refers to a direction perpendicular to this, but these are for convenience and may be reversed.

Next, the above constituent members and their functions will be explained.
The cathode 12 is, for example, a direct heating type in which a thin tungsten wire of several tens of liters in diameter is directly coated with an electron radioactive substance such as (Ba, Sr, Ca)0, or a thin tungsten wire coated with a heat-resistant insulating material such as alumina. There is either an indirectly heated type in which the heater wire is coated with an electron radioactive substance in a nickel sleeve, etc. that covers the heater wire, and in the case of a directly heated cathode, it is directly energized, and in the case of an indirectly heated cathode, there is a built-in heater wire. By energizing the heated heater wire, the electron radiation temperature can be increased to 600~
It is heated to 800°C. In addition, in the case of an indirectly heated cathode, the cathode is constantly energized, but in the case of a directly heated cathode, the cathode is selected and the potential is made equal across its longitudinal direction. It will be done. In FIG. 1, an indirectly heated cathode 12 is shown, and the symbol 12a is a heater wire, and the symbol 12 is a heater wire.
b or sleeve.

The electron extraction electrode 18 is a metal plate-like electrode or cathode 12 having a plurality of through holes 18a for passing electrons.
It consists of multiple strip-shaped electrodes divided horizontally in correspondence with each other.

It is used to focus and extract electrons from the cathode 12 by applying a positive potential to the cathode 12 during electron emission. In FIG. 2, reference numeral 19 is an insulating spacer that supports the electron extraction electrode 18 on the back plate 14.

The vertical deflection electrodes 20 are arranged to sandwich the cathode 12,
A pair of wedge-shaped metal electrodes, or a pair of wedge-shaped metal electrodes, have a concave portion 20a that is approximately parallel to the screen surface of the front plate 24 and a deflection portion 20b that is inclined toward the cathode 12 or is approximately perpendicular to the screen surface. It consists of a pair of electrodes formed by forming a metal plate or metal film on an insulating substrate provided in a substantially vertical direction, and focuses the electrons extracted through the electron extraction electrode 18 and deflects them in the vertical direction to generate a positive It is used to deflect and scan a predetermined rask area of the phosphor screen provided on the face plate 24.

The horizontal control electrode 16 is located closer to the back plate 14 than the cathode 12,
Consisting of a plurality of electrodes arranged perpendicular to the stretching direction of the cathode 12, this horizontal control electrode 16 is vertically divided into approximately the same number as the horizontal resolution of this device, and
It is used to horizontally control a sheet-shaped beam taken out from the electron extraction electrode 18 or a plurality of divided beams divided by the plurality of through holes 18a of the electron extraction electrode 18 and deflected in the same direction. The horizontal control electrode 16 basically consists of an electrode piece formed on the back plate 14 by depositing or etching a metal or conductive material.

The front plate 26 is made of a transparent insulating material such as glass, which is provided facing substantially parallel to the plane constituted by the plurality of cathodes 12, and is integrated with an anode 22 such as thin film aluminum with a metal back. The phosphor surface 24 is attached to this front plate 2.
It is provided all over the top of 6.

Next, the operation of the above device will be explained. In this device, the cathode 12. The set of vertical deflection electrodes 20 is used as a scan electrode, and the horizontal control electrodes 16 are used as data electrodes, and by performing line-sequential scanning using the scan electrodes and data electrodes, any image can be displayed. Ru. For example, (Sl), (S2), (S3) shown in FIG.
, (S4) are connected to display an image on the screen surface, and the electron beam scanning is performed by first changing only the potential of the cathode 12 corresponding to the region (S,) to approximately the potential of the electron extraction electrode 18. On the other hand, the potential of the cathode 12 in the remaining region (S2) to (S, ) is lowered by the electron extraction electrode 1.
By setting the cutoff potential to the potential of 6,
Electrons are extracted only from the cathode 12 of (S, ), and immediately after that, the negative! ! A gradually increasing copper-covered, step-like, or triangular wave voltage is applied to one side of a pair of vertical deflection electrodes 20 arranged to sandwich the cathode 12, and the deflection electrodes on the opposite side facing each other with the cathode 12 in between are applied. The cathode 12 corresponding to the area of 0th order (S2) is selected and deflected and scanned in the same manner, and the following (S3) , (S4) are sequentially scanned to form one frame. In addition, a video signal is sent to the horizontal control electrode 16 in synchronization with the scanning timing of each area.For example, when scanning the area (S2) in FIG. teeth,
At the timing when the electron beam is deflected and scans each predetermined pixel row, the horizontal control electrode 16 and the cathode 1
The potentials of at least one or more of the electron extraction electrode 18 and the electron extraction electrode 18 are simultaneously modulated to display a halftone image.

Next, a preferred electrode support structure of this display device will be described with reference to Section 3 and FIG. 4. Incidentally, this electrode support structure has been proposed separately by a non-applicant.

As can be seen from FIGS. 3 and 4, the horizontal control electrode 16 is formed by forming a thin film using a metal sputtering method, electron beam evaporation, plating, etc. on the base portion 28 of the back plate 14, or by applying an etched thin plate metal to a low melting point frit. The electron extraction electrode 18 and the deflection electrode 20 are mounted on the control electrode 16 via a spacer 19 or the like. Note that the back plate 14 has the base portion 28, the frame portion 30, and the recessed portion 32 integrally formed by pressing molten glass in advance.

Meanwhile, the cathode support terminal means is assembled in the following order.

The cathode support terminal means 34 consists of a retaining member 36 that retains one end of the linear cathode 12 and an extension member 38 that extends the other end of the linear cathode 12.

As shown in FIGS. 5(A) and 5(B), a fixing agent 40 is formed by screen printing a paste-like frit glass at a predetermined position on the back plate 14 or using a dispenser having a nozzle for discharging the paste, After evaporating the quick-drying binder components such as isoamyl nitrate contained in the fixing agent 40 of this Bullitt glass paste by drying at around 100°C, the 426 alloy (42% nickel, 6% Retaining member 36 or extension member 3 made of chrome, balance iron) or stainless thin plate
In the electrode part 1 drawing shown in 8, a retaining member 36 is placed on the adhesive 34 and temporarily fixed using an appropriate holding jig (not shown), and then a high-temperature sublimable binder component such as nitrocellulose is pre-baked at 300 to 380°C. After removing in the process,
The electrode parts 34 are fixed to the back plate 14 by performing final firing at a temperature of about 400 to 450"C.As another method, as shown in FIG. After applying the paste, the electrode component (retaining member) 36 having the through hole 36a is temporarily fixed, and then the frit glass paste is dried, temporarily fired, and one piece is fired to fix the electrode component 36. When the electrode part or the extension member 38 is used, both ends of the linear cathode 12, which is attached in the same manner, are fixed to the retaining member 36 and the extension member 38, respectively, either directly or through a suitable metal piece by spot welding or the like. be done.

[Invention or problem to be solved]

However, the cathode support terminal means proposed above has the following problems.

(1) Oxidation of the electrode during electrode formation.

Frit glass is essentially low-melting solder glass with lead oxide as its main component, and is mixed with a fast-drying and high-temperature sublimation binder component to form a paste. Except for the drying process, which is a process for removing quick-drying binder components that can be dried at high temperatures, in the pre-firing process, high-temperature sublimable binder components can only be completely removed in a high-temperature atmosphere of 300°C or higher in the air, and Decomposition of lead oxide occurs during the main firing process, so if you try to directly fix the electrode parts to the glass housing using frit glass, there will be a problem that the electrode will oxidize during the pre-firing and main firing processes of the frit glass. .

Therefore, each step is carried out at the lowest possible temperature and in the shortest possible time.
Preliminary firing is performed in the air, and main firing is performed in an inert gas atmosphere. Therefore, deterioration of the electron emission ability of the cathode could not be avoided.

Furthermore, although materials such as the frit glass that is the fixing agent, the panel glass (rear plate) that is the substrate, or the 426 alloy that is the electrode are set to have very close coefficients of thermal expansion, Since it is not possible to completely match the thermal expansion coefficients over the entire temperature range, if the electrode assembly is designed so that they are completely integrated over a length of several mm or more and a width of several mm, the base Cracks occur in the panel glass.

Therefore, if it is necessary to integrate the electrode over a long distance, it is generally done to design the electrode so that the stress can be relaxed in the middle by applying frit glass intermittently to a part of the section. .

For example, the terminal of the cathode 12 corresponds to this case,
Although the middle part is left unfixed, the surface of the middle part, especially on the back plate side, is a place where the distance between the back plate and the electrode is narrow and the air resistance is large, so it is heated with inert gas during the main firing. It is difficult to replace this area, and therefore, oxidizing gas generated from the binder components tends to accumulate in this area. It had become.

Also, this oxide film can be removed with nitric acid, hydrochloric acid, etc., but since friud glass is easily attacked by these acids, this treatment cannot be applied to an assembly in which the frit is fixed to the back plate. Polishing means, which is another means for removing the oxide film, cannot be used because the electrodes are made of precision thin metal plates and are easily deformed.

In addition, in the display device proposed above, in order to reduce the area of the sealing portion, which is the frame of the back plate, and to increase the implosion resistance, the back plate 14 has a recess 32, and therefore the cathode structure is Or support for a getter etc. not shown is provided on this back plate 14.
Since these parts are installed in the recesses 32 of the back plate 14, the back plate 14
It is difficult to perform screen printing or transfer printing in the recess 32 of the back plate 14, and the process is complicated and expensive to insert the screen or transfer surface, which is the printing means of the printing device, into the recess 32 of the back plate 14. In addition to this, there is a drawback that the yield is reduced.

Further, when assembling the electrodes, it is necessary to attach a plurality of retaining members to the recesses 32 of the back plate 14, resulting in low assembly accuracy and the need for special jigs, which are expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for assembling a cathode structure of a flat panel cathode ray display, which avoids the above-mentioned drawbacks, does not cause oxidation of electrodes, and is easy to assemble.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a plurality of linear cathodes stretched substantially parallel to each other, and a back plate provided in a direction orthogonal to the cathodes. a control electrode that deflects the electron beam in a direction perpendicular to the linear cathode, a deflection electrode that deflects the electron beam in a direction perpendicular to the linear cathode, and a phosphor layer that is provided on the front plate and is integrated with the anode. In a flat panel cathode ray display device that scans small image areas and connects them to obtain a single image, the back plate has a recess formed between a frame and a base on which control electrodes are provided. A metal assembly pedestal is attached to the recessed portion of the back plate, a cathode support terminal means is fixed on the assembly pedestal by welding, and a plurality of linear cathodes are stretched over the cathode support terminal means. The present invention provides a method for assembling a cathode structure of a flat-panel cathode ray display device characterized by the following features: (Function) As described above, the back plate has a recess formed between the frame and the base portion on which the back electrode is attached. If the cathode support terminal means is attached not directly to the recessed portion of this back plate but via a metal assembly base, the cathode support terminal means will be free-standing.
Since the electrodes are attached in a non-oxidizing atmosphere such as by welding, rather than using a glass fixing means, there is no problem of oxidation of the electrodes, especially the cathode.

In addition, since the cathode support terminal means does not require the use of a frit glass fixing means and does not require expensive screen printing or transfer printing within the recess of the back plate, the electrode structure can be assembled at low cost and with high yield. This also improves assembly accuracy.

(Example) To explain the present invention in detail with reference to an example, FIG. 6 shows a cathode structure assembled by the assembly method according to the present invention. A cathode ray display device is basically exactly the same as shown in FIGS. 1 and 2, and includes a plurality of linear cathodes 12 stretched approximately parallel to each other, and a plurality of wires. The back plate 1 is placed in a direction perpendicular to the direction in which the shaped cathode 12 is stretched.
4 and a plurality of horizontal control electrodes 16 provided on the linear cathode 1
A vertical deflection electrode (not shown in Fig. 6) that deflects the electron beam in a direction perpendicular to 2 and a phosphor layer (not shown in Fig. 6) provided on the front plate and integrated with the anode. ), and the electron beam is connected to the linear cathode 1.
The system scans approximately the same number of small image areas as 2 and connects them to obtain one image. In addition, in FIG. 6, it is shown that an electron beam extraction electrode 18 is further provided.

The back plate 14 has a base portion 2 on which the horizontal control electrode 16 is attached.
8 and the frame: flA 30, and a plurality of linear cathodes 12 are stretched over cathode support terminal means 34 attached to this recess 32 of the back plate 14.

In the assembly method of the present invention, a metal assembly pedestal 42 is attached to the recess 32 of the back plate 14, the cathode support terminal means 34 is fixed to the assembly pedestal 42 by welding, and the plurality of linear cathodes 12 are attached to the cathode support terminal means. 34 and install it.

Next, to describe the method of the present invention in more detail, the back plate 1
4 is made of an insulating substrate such as glass or a material such as metal coated with insulation, as in the conventional case. As shown in FIG. 7(A), the back plate 14 includes a pedestal 28 or a sealing surface on which a horizontal control electrode 16 as a back electrode made of a conductive film such as vapor-deposited metal or etched thin plate metal is attached. Is it possible to make it from a glass structure that is integrally press-molded so that it has almost the same height as the frame part 30?
The substrate portion, frame portion, and base portion may be processed separately, and these may be integrally formed by assembly means such as frit glass sticking or thermal welding.

Horizontal control electrodes 16 having approximately the same number as the horizontal resolution are arranged vertically parallel to each other on the base portion 28 of this back plate 14, and these horizontal control electrodes 16 are made of low melting point frit glass (not shown) or the like. The back plate 1 is fixed by the fixing means of
The electron extraction electrode 18 and the vertical deflection electrode 20 are stacked on the horizontal control electrode 16 by spacer means (not shown).

The cathode support terminal means 34 also consists of a retaining member 28 and an extension member 30, which are extended and fixed at both ends of the cathode 12, as in the prior art.

An example of an assembly base 42 used in the present invention is shown in FIG. This assembly pedestal 42 has a thickness of 0.5 to 2 mm.
It is made from a rectangular 426 alloy plate or stainless steel plate with an area of 10 mm, and is punched and pressed so that it has legs with a length of 0.5 to 1.5 mm in the direction toward the back plate 14 at the corners. Form.

The glass back plate 14 is heated and softened in advance in a tunnel furnace controlled at a temperature of 600 to 800°C, and the assembly pedestal 42 is heated to a temperature of 100 to several hundred degrees Celsius higher than the temperature of the back plate 14. The legs 42a are heated in advance by high frequency heating or a burner, and the legs 42a are completely buried in the predetermined positions of the recesses 32 of the back plate 14, as shown in FIGS. It is press-fitted using an air chuck and a press-fitting jig so that it is almost in contact with the recess 32 of the back plate 14, and then it is slowly cooled and integrated into the back plate 14.

As shown in the upper right of FIG. 9, the retaining member 36 or the extension member 38 is fixedly attached to the member 44, or as shown in the upper left of section 9, the retaining member 36 or the extension member 38 is attached with a retaining mechanism. or may have an extension mechanism;
In FIG. 9, reference numeral 36A (38A) indicates a portion having a retaining mechanism or an extension mechanism. For mounting a plurality of members 44, the members 44 are connected to each other by a connecting portion 44a, and for these mountings, the members 44 are placed on an assembly base 42 while being connected by the connecting portion 44a, in alignment with appropriate positioning marks (not shown), and laser welding is performed. , spot welding or brazing, or the like. In this manner, after the member 44 and the assembly base 42 are integrated, the connecting portion 44a is separated by laser cutting means or the like.

The cathode 12 is attached to the retaining member 3 attached in this way.
6 and the extension member 38 in a stretched manner. still,
In FIG. 6, reference numeral 46 is a positioning member for setting the height and vertical position of the cathode 12 stretched over the back plate 14. FIGS. 10 (A) and (B) are assembly pedestals used in the present invention. Another modified example will be shown. In the embodiment shown in FIG. 10(A), the assembly base 42A has the form of a pin, and the mounting member 44 is supported by being engaged with the annular base of the assembly base 42A in the form of a pin. In this case, the pin-shaped assembly base 42A has a tapered embedded part that is embedded in the recess 32 of the back plate 14. In the embodiment shown in FIG. 10(B), the assembly pedestal 42B is L-shaped, and a fixing pin 46 embedded in the four parts 32 is attached to the bottom of the assembly pedestal 42B.

In this embodiment, the assembly base 42 or the recess 32 of the back plate 14
This is preferable because it prevents oxidation from forming on the back surface of the assembly base 42. Furthermore, even if an oxide film forms on the assembly pedestal 42 during storage at room temperature for a long period of time, the back plate 14 integrated with the assembly pedestal 42 should be immersed in a nitric acid bath heated to, for example, 40°C. The oxide film on the assembly base can be easily removed by blasting or puff polishing.

In addition, the surface of the assembly base 42 on the back plate 14 side is
It may be buried instead of in contact with the panel, but in this case, cracks may occur during the heat treatment process such as panel baking, so it is necessary to assemble the It is preferable that the pedestal is provided with stress relieving means such as notches.

〔Effect of the invention〕

According to the present invention, as described above, the assembly pedestal is attached to the recessed portion of the back plate, and the cathode support terminal means is attached to the assembly pedestal, so that the following effects are produced.

(1) The problem of electrode oxidation is eliminated.

Rather than directly attaching the cathode support terminal means to the recess of the back plate, the cathode support terminal means is mounted on the assembly pedestal attached to the recess, so it is not exposed to the oxidizing atmosphere caused by frit glass firing. Therefore, problems of electrode oxidation and cathode contamination do not occur.

(2) It is not necessary to apply screen printing to the concave portions of the back plate.

Since frit glass is not used to fix the cathode, costly processes such as screen printing and transfer printing are not required, and yields are improved, and thermal processes such as low melting point solder glass firing are not required. Eliminates electrode slippage and improves assembly accuracy.

[Brief explanation of drawings]

1 and 142 are exploded perspective views and sectional views of a cathode ray display device previously proposed by the present applicant, and FIGS. 3 and 4 are enlarged perspective views of cathode support terminal means previously proposed by the present applicant. 5(A) and 5(B) are perspective views showing different installation states of the electrode parts of the cathode support terminal means of FIGS. 3 and 4, and FIG. 7(A) and 7(B) are respectively a perspective view and a side view showing how the assembly pedestal used in the present invention is installed, and FIG. 8 is a perspective view of the assembly pedestal used in the present invention. Figure 9 is an exploded perspective view explaining the present invention in detail, Figure 1O (
A) and (B) are perspective views showing different modifications of the assembly base used in the present invention. 10-----1 cathode ray display device, 12-----cathode, 1
4---One back plate, 16---Horizontal control electrode, 18
----One electron extraction electrode, 20----Vertical deflection electrode, 22---m-Anode, 24----One phosphor layer, 2
6 Front plate, 28 ---- One unit part, 3O Frame part, 32 - One recessed part, 34 - Cathode support terminal means, 36 ---- Retaining member, 3
8----1 extension member, 42---m-assembly pedestal.

Claims (1)

[Claims] a plurality of linear cathodes stretched substantially parallel to each other; a control electrode provided on a back plate in a direction perpendicular to the cathodes; and a deflection electrode for deflecting the electron beam in a direction perpendicular to the linear cathodes. and a phosphor layer provided on the front plate and having an integrated anode, the electron beam scans approximately the same number of small image areas as the linear cathode, and these areas are connected to obtain one image. In the flat-panel cathode ray display device, the back plate has a recess formed between a pedestal portion on which the control electrode is provided and a frame portion, and a metal assembly pedestal is attached to the recess portion of the back plate. . A method for assembling a cathode structure of a flat panel cathode ray display device, characterized in that a cathode support terminal means is fixed on the assembly pedestal by welding, and the plurality of linear cathodes are stretched over the cathode support terminal means.