JPH0494035A - Manufacture of plate type cathode ray display device - Google Patents

Abstract

PURPOSE:To prevent a pressure resistance support body from making contact with a screen and damaging an anode by interposing a pressure resistance support means between a front face plate and a back face plate during the exhaust and the heat- treatment process of an envelope, removing the pressure resistance support means after the envelope has been cooled, and thereby letting the pressure resistance support body abutt against the front face plate having the screen. CONSTITUTION:The envelope 18 of a display device 10 is equipped with a pressure resistance support means 24 which withstands inner pressure. And an electrode body structure 20 has been integrally mounted onto a back face plate 14, the back face plate 14 is hermetically sealed with a front face plate 12. An upper and a lower external hold means 30 and 30' are formed with a plurality of holes bored in surfaces faced to the front face plate 12 and the back face plate 14, and with stainless chassis 31 which includes chap pipe 31b for evacuating the hold means so as to be vacuous. The envelope 18 is held by both of the upper and lower hold means 30 and 30', and the both surfaces of the envelope 18 can thereby be fixed by evacuating the insides of the external hold means so as to be vacuous. Following which, after the envelope has been mounted onto an envelope carrier, absorbent gas is exhausted out with heat applied, so that panel baking is thereby ended up.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a method for manufacturing flat cathode ray display devices such as flat CRTs and fluorescent display tubes for displaying single characters and graphics.

(Prior art) Cathode ray display devices such as flat CRTs, fluorescent display tubes, etc.
Since it consists of a flat vacuum tube (panel), the thickness of the envelope, especially the thickness of the periphery of the front and back plates that have a screen that forms the flat part, must be increased to prevent the panel from being crushed by atmospheric pressure. However, this method has the disadvantage that the panel becomes heavier and thicker, making it impossible to meet the demands for thinner and lighter display devices.

Several display devices have been proposed that avoid these drawbacks and can achieve large screen thickness and weight reduction.

These display devices are as shown in FIG.

an envelope 18 consisting of a front plate 12, a back plate 14, and a side wall 16 that are arranged substantially parallel to each other at a predetermined interval;
An electrode assembly 20 includes an electron source disposed in the envelope 18 and performs a plurality of beam controls such as deflection, focusing, diffusion, acceleration, beam amount control, etc. of the electron beam emitted from the electron source. , a fluorescence emitting means 22 consisting of a phosphor provided on the front plate 12 and a transparent anode metal-backed or separate thereon, and a pressure-resistant support means for pressure-resistant supporting the inside of the envelope 18. It is equipped with 24.

The pressure-resistant support means 24 is a pressure-resistant support made of an insulator or a conductor in the form of a plate, a bottle, or a bottle protruding from the bottom surface of the plate, which is provided in the envelope IB and supports the electrode assembly 20 with pressure. 26, this pressure-resistant support means 24 has various functions in addition to the pressure-resistant support function, namely, an electron beam deflection function or an electron beam acceleration function.

As shown in FIG. 1, in this display device, the front plate 12 or the back plate 14 and the side wall 16 are fixed by fixing means such as low melting point solder glass, sealing, or welding, or the front plate 12 and the side wall 16 are fixed together. Alternatively, the back plate 14 and the side wall 16 are integrally molded, and the electrode structure 20 provided with the pressure-resistant support 26 is housed while the electrode structure lead-out terminal (not shown) is disposed, and the front plate 12 and the back plate 14 are airtightly sealed. stopped and assembled,
Thereafter, the envelope 18 thus formed was
The inner surface of the envelope 18 or the electrode structure is placed in a baking oven controlled at a temperature of 10°C to 450°C, and the inside is evacuated through an opening such as an exhaust pipe 28 provided in the side wall 16 or the like of the envelope 18. A so-called panel baking is carried out to remove factors that reduce the degree of vacuum, such as moisture and carbon dioxide adsorbed on the 20, and furthermore, for example, in the form of an electron source or a hot cathode with an oxide applied in the form of carbonate. In some cases, a so-called cathode baking process is performed to decarboxylate and activate the cathode by heating, and a current is passed from the cathode to the surface of these electrodes using a plurality of other electrodes as the anodes relative to the activated cathode. Emissive baking is performed to remove gases such as water vapor and carbon oxide adhering to the surfaces of these plurality of electrodes, and assembly of the display device is completed by these plurality of treatments.

(Problems to be Solved by the Invention) However, the above conventional manufacturing method has the following problems.

First, as shown by the dotted line in FIG. 1, a large compressive stress is applied to the center of the panel during evacuation after one assembly,
In addition, large warpage occurs in the back plate 14, and the pressure support 26 at the center of the panel buckles or the side wall 16 falls inward, causing separation between the side wall 16 and the front plate 12 or the back plate 14. Additionally, there is a problem in that the phosphor of the fluorescent light emitting means 22 on the front plate 12 is seriously damaged by the movement of the pressure-resistant support 26.

In order to avoid these problems, the present applicant has proposed that, as shown in FIG.
4 by vacuum suction means 30, 30'' to create a pressure difference between the inside and outside of the display device (
#Refer to Gansen 1-214837).

According to this method, the pressure-resistant support 26 during evacuation
The problems such as buckling of the panel and collapse of the side wall 16 will be almost completely resolved, or will the temperature rise of the envelope during the panel baking process, which is essential for multiple baking processes to be performed subsequently, be performed at high temperatures? At this time, differences in thermal expansion and thermal contraction behavior occur due to minute differences in coefficient of thermal expansion or non-uniformity in thermal distribution between the electrode constituent material and the envelope, resulting in contact with the pressure support 26. Vulnerable 3000-500
The aluminum metal back film (anode) with a thickness of 0.5 mm was partially broken, resulting in the display screen being dotted with areas that did not emit light.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a flat panel cathode ray display device that can avoid the above-mentioned drawbacks.

Means for Solving Cap 1) In order to solve the above problems, the present invention provides an envelope including a front plate and a back plate having a screen including fluorescent light emitting means, and a front plate of this envelope. In the manufacturing method of a flat panel cathode ray display device, the front plate and the back plate are disposed between the front plate and the back plate, and the pressure supporting means is composed of a plurality of pressure-resistant supports disposed between the electrode structure and the back plate. A holding means is arranged between the front plate and the back plate so that the distance between the front plate and the back plate is larger than the height of the pressure-resistant support, and after the envelope has cooled, the holding means is removed and the pressure-resistant support is The present invention provides a method for manufacturing a flat panel cathode ray display device, characterized in that a support is brought into contact with a front plate having a screen.

The holding means may be of a vacuum suction type, or may consist of a holding member such as a reinforcing rib provided on the back plate for mechanically holding and fixing.

(Function) In this way, the external holding means having functions such as vacuum adsorption or mechanical gripping allows the pressure-resistant support configured to have a length that does not touch the screen on the front plate before the envelope is evacuated. Even during the heating process, which overlaps with the vacuum evacuation process, the anode remains in almost the same state and does not come into contact with the screen, so the anode is not destroyed and the envelope is heated to near room temperature, where the difference in thermal expansion coefficient of the envelope almost disappears. After cooling, the holding means is removed from the display device and the #pressure support is brought into contact with the screen, thereby providing normal pressure support.

(Example) An example of the present invention will be described in detail with reference to the drawings.
FIG. 3 shows an embodiment of the present invention.

This display device 10, like the display 11M of the prior art,
It consisted of a front plate 12 made of glass with a thickness of 3 to 4 mm and having a screen 22 containing a fluorescent light emitting means, which will be described later, a back plate 14 made of glass as well, and a side wall 16 having a glass exhaust pipe 28 for evacuation. It includes an envelope 18 and an electron source disposed within the envelope 18, and deflects, focuses, and diffuses the electron beam emitted from the electron source.
An electrode assembly 20 for performing multiple beam controls such as acceleration and beam amount control, and a phosphor including an anode consisting of a phosphor provided on the front plate 12 and a transparent electrode metal-backed or separate thereon. It includes a light emitting means 22 and a pressure supporting means 24 for supporting the inside of the envelope 18 against pressure.

Next, in the manufacturing method of the present invention, as in the conventional case, the front plate 12 and the side wall 16 are sealed with crystalline low melting point solder glass with the lead-out terminal 32 for applying an anode voltage sandwiched therebetween. Thereafter, a guard band made of three-color phosphor stripes and graphite arranged between the phosphor stripes is provided on the inner surface of the front plate 12 to a thickness of 10 to 20 ILm by a printing method, and a metal back film serving as an anode is further applied. Filming treatment for smoothing, aluminum metal back,
The front plate 12 is formed by performing a phosphor screen baking process to burn off the phosphor screen and filming liquid. Furthermore, after the electrode assembly 20 is integrally attached to the back plate 14 in a separate process, the back plate 14 is hermetically sealed to the front plate 12. In addition, in this electrode structure 20, pressure-resistant supports 26 whose walls are approximately the same thickness as the guard band width and whose surfaces are coated with a conductive material or a resistive material made of carbon, metal, etc., are installed every 20 to 40 mm to prevent charge-up. The length thereof is 0.2 mm smaller than the distance between the electrode structure 20 and the screen 22.

As shown in FIGS. 2 and 3, the upper and lower external holding means 30, 30' have a large number of openings 31a facing the front plate 12 and the rear plate 14, and a tip tube 31 for vacuum suction.
It consists of a stainless steel casing 31 having b. The envelope 18 is sandwiched between the two sets of upper and lower holding means 30 and 30', and the inside of the external holding means is held at a pressure of 10-' Torr.

Both sides of the envelope 18 are fixed by applying a moderate amount of vacuum. This vacuum suction may be accomplished using a rotary pump mounted on an envelope carrier, such as a cart (not shown), as is known to those skilled in the art.

Next, while the inside of the envelope was evacuated to a high vacuum of 10-'1 Torr using a rotary pump and an oil diffusion pump, the envelope was attached to an envelope carrier (not shown), and after 350 ~
The internal temperature of the envelope is raised by placing it in a flow-air belt furnace controlled at 450°C, and the inside of the envelope is maintained at the same temperature for about 1 hour, so that the inside of the envelope, electrode structure, etc. Panel baking is completed by exhausting the adsorbed or occluded gas.

After this panel baking process or during the cooling process after this panel baking process, cathode baking process and emission baking process are performed, and the exhaust pipe is melted to complete the display device 10.

Holding the front plate 12 and the back plate 14 by suction by the holding means 30, 30' is such that the temperature of the envelope is sufficiently lowered from the start of temperature rise in the above process, and the thermal expansion and temperature distribution of the envelope are substantially reduced. FIG. 4 shows another embodiment of the present invention, and the display device in this embodiment has a fluorescent screen 22 and a side wall as shown in FIG. 16 or integrated plate thickness 5
A front plate 12 made of glass with a thickness of 2 mm, a back plate 14 made of a flexible metal coated with a 2 mm thick plating or glass, etc. for insulation and a function of filling pinhole defects, and a side plate 1116. An envelope 1B composed of a glass exhaust pipe 28 for evacuation provided;
The envelope 18 includes an electron source disposed within the envelope 18, and deflects, focuses, diffuses, and accelerates the beam emitted from the electron source.
An electrode assembly 20 for controlling a plurality of beams such as beam amount control, and a fluorescent light emitting means 22 having an anode consisting of a phosphor provided on the front plate 12 and a transparent electrode that is metal-backed or separately attached. and pressure-resistant support means 24 for pressure-resistant supporting the inside of the envelope 18.

This display device is assembled as follows. First, as in the past, a guard band made of three-color phosphor stripes and graphite arranged between the phosphor stripes is provided on the inner surface of the front plate 12 by a screen forming method such as a slurry coating method. The front plate 12 is formed by performing a metal backing process, a metal backing process, and a phosphor screen baking process. On the other hand, the electrode structure 20 formed in a separate process is placed in the space between the front plate 12 and the back plate 14 on the back plate 1.
4 and placed and sealed. Note that this electrode structure 20
The bottle-shaped pressure-resistant supports 26 of the pressure-resistant support means 24 are arranged at intervals of 20 mm and have a diameter slightly smaller than the width of the guard band and coated with a conductive or resistive material made of carbon, metal, etc. on the surface. is set to be 0.2 mm smaller than the distance between the electrode assembly 20 and the screen 22.

The envelope 18 constructed in this way has holding means 30 and 30' provided with a large number of openings 31a for vacuum suction, as in the embodiment shown in FIG. and the inside of the external retaining means is set to 10” Torr through the exhaust pipe.
First, the inside of the envelope was evacuated to a high vacuum of 10 Torr using a rotary pump and an oil diffusion pump, and the envelope was attached to an envelope carrier (not shown). The inside of the envelope 18 is placed in a flow-air belt furnace controlled at ~450°C, and the inside of the envelope is maintained at the same temperature for about 1 hour. Then, the gas adsorbed or occluded by the electrode assembly 20 and the like is discharged, and panel baking is completed.

Furthermore, cathode baking and emission baking are performed, and the exhaust pipe 28 is electrically sealed and fused to complete the display device 11O.

Holding the front plate 12 and the back plate 14 by suction by the holding means 30° 30' means that the temperature of the envelope is sufficiently lowered from the start of temperature rise in the above process, and the thermal expansion and temperature distribution of the envelope are substantially reduced. This process is carried out until the temperature reaches 100°C or below, which is not a problem.At this time, since the back plate 14 is made of a metal plate that is relatively easily deformed, it is fine if the area of the envelope is narrow, but if the exhaust area is wide. Then.

When the vacuum holding means 30' has one vacuum chamber,
Differences in conductance within the suction surface can cause uneven lifting height, so for example, the lifting height near the exhaust port may be larger than other areas, and at the same time permanent deformation may occur due to heat. Means 30
As shown in Figure 4, the vacuum chamber at 30°
The back plate 14 is partitioned by a or has multiple exhaust ports.
It is preferable to control the degree of deformation within the suction surface.

FIG. 5 shows yet another embodiment of the invention, in which mechanical retaining means 36 are used in place of the upper vacuum suction means 30'' of the embodiments of FIGS. 3 and 84. There is.

That is, in the embodiment shown in FIG. 1, the back plate 14 is made of metal or glass and has a reinforcing rib 34 having a through hole 34a. As shown in FIGS. 5 and 6, the holding means 36 is made of a metal prism, channel material, or O-shaped material having a large number of hooks 38.
8 into the through hole 34a to mechanically prevent the reinforcing rib 34 from falling inward. In this way, instead of the vacuum suction holding means 30° shown in FIG. Since the back plate 14 is held by being inserted into the through hole 34a of the pressure support 26, the pressure support 26 does not come into contact with the screen 22 even during exhaust and heat treatment of the envelope.

(Effects of the Invention) According to the present invention, as described above, since the pressure-resistant support means does not come into contact with the screen during the exhaust heat process of the envelope, thermal expansion and heat can occur between the electrode assembly and the envelope. Even if there is a difference in shrinkage, the screen will not be damaged, and a high-quality display device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a method of manufacturing a flat panel cathode ray display device according to the prior art, FIG. 2 is an exploded perspective view showing a manufacturing method previously proposed by the applicant, and FIG. A cross-sectional view showing a method of manufacturing a device, Figure #14 is a cross-sectional view showing a method of manufacturing a display device according to a different embodiment of the present invention, and Figure 5 is a cross-sectional view showing a method of manufacturing a display device according to another embodiment of the present invention. FIG. 3 is a perspective view of the main parts of the method. FIG. 6 is an enlarged side view of the assembled state of the holding means in the embodiment of FIG. 5. 10----1 flat plate cathode ray display device, 12-111 front plate, 14---back plate, 16---side wall,
1 B-----1 envelope, 2゜--1--electrode structure, 2
2-----Screen, 24---Pressure support means, 26--Pressure support, 28--m-Exhaust pipe,
3°, 30'-----Vacuum suction holding means, 34---
m-Reinforcement rib, 36--Mechanical retention means. 7th a1 1st 2nd gl

Claims (1)

[Claims] A pressure-resistant device comprising: an envelope including a front plate and a back plate having a screen including fluorescent light emitting means; and a plurality of pressure-resistant supports disposed between the front plate and the back plate of the envelope and supporting an electrode structure. In the method of manufacturing a flat cathode ray display device, the distance between the front plate and the back plate is maintained to be larger than the height of the pressure-resistant support during the evacuation of the envelope and the heat treatment process. A holding means is disposed between the front plate and the back plate so that the enclosure is cooled, and the holding means is removed to bring the pressure-resistant support into contact with the front plate having the screen. A method for manufacturing a flat panel cathode ray display device, characterized by: