JPS6055944B2 - Manufacturing method for cathode ray tubes, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing cathode ray tubes, fluorescent display tubes, etc., and in particular, a method for manufacturing cathode ray tubes, fluorescent display tubes, etc. This article relates to a series of manufacturing methods that can efficiently apply a compound called "mixture".

An example of a conventionally used method for applying a mixture to the sealed end face of a funnel will be explained with reference to FIG.
In the figure, the funnel 1 is installed so as to rotate with the sealed end surface 2 facing a panel (not shown) facing upward.
The mixture 4 is dropped onto the sealing end surface 2 from the nozzle 5 of a container 3 containing the mixture 4 in the vicinity of the sealing end surface 2, and a predetermined amount of the strip-shaped mixture 7 is applied onto the sealing end surface 2.

After drying the funnel coated with the strip-shaped mixer 7 at room temperature, a panel (not shown) is accurately placed on the sealed end surface 2 of the funnel 1 via the strip-shaped mixer 7 using a positioning jig or the like and heated. Then, the panel and funnel 1 are sealed to complete the cathode ray tube envelope. To explain in more detail, the composition of the mixer 4 used is as follows, for example.

That is, w parts of frit glass powder are added to 1 part of a liquid mixture consisting of 1 part of nitrocellulose and 99 parts of aluminum isoacetate or butyl acetate, and mixed well to create a predetermined mixer 4, and this mixer 4 is used to seal the funnel. After coating the entire surface of the end surface 2 by discharging from the nozzle 5 and drying at least three powders at room temperature, the panels whose sealed portions are opposite to the sealed end surface 2 of the funnel are stacked and heated. During the heating process, nitrocellulose first decomposes and evaporates, resulting in an additional 400%
The frit glass melts at ~450°C. This is slowly cooled to complete the sealing and complete the cathode ray tube envelope. There are two methods for applying the mixture: a manual method and a mechanical method, both of which are discharge methods (dropping methods). That is, Mixture has a high specific gravity (for example, 5) and a viscosity that is not very high, that is, in the above-mentioned composition, it is, for example, about 4000 poise at 20° C. with a rotational viscometer of 10 RPM.

Therefore, the inner diameter is 6Tfr! Container 3 having a nozzle 5 of approximately nφ
If you use it, it will fall easily. Utilizing this property, a certain amount of mixture is applied to the sealing surface 2 while the funnel 1 is rotated in the direction of the arrow. Some containers are attached by hand, while others are attached to a machine that operates along the side of the funnel end to apply the product. However, the use of the above-mentioned conventional coating method has the following drawbacks. In other words, the viscosity of one mix may change, the amount in the container may change, the circumferential speed of the funnel may be uneven, the area where the coating starts and the area where the coating is finished always overlap, or there are areas that are not coated, etc. The amount is not uniform, and it takes time to wipe off the overflowing mixture. Parts with a large amount of 2 applied will protrude when sealed with the panel, making it easy to destroy the cathode ray tube.

3. I would like to make the frit layer thinner to prevent breakage and frit penetration, but this is not possible due to the coating method.

4. It is very difficult to mix funnels with different outer diameters in the same coating device.

5 local. Areas where a large amount of paint is applied tend to form, and permanent deformation during sealing is concentrated, making it easy to destroy the cathode ray tube.

6. If the amount of coating is small and the frit does not cover the entire surface of the sealing part, the withstand voltage will be small and the frit will penetrate (a high voltage applied to the anode inside the tube, for example 30 KV, will pass through the weak frit glass layer to the outside). Melt the frit with Joule heat and add 0.5TWt x 0.2TH to the same part!
(This causes a through hole at position f&), resulting in damage or air leaks.

The object of the present invention is to eliminate the above-mentioned conventional drawbacks, effectively apply a uniform meat dust to the sealed end surface of a funnel, etc., and obtain a high-quality cathode ray tube, etc.

Next, an embodiment of a transfer type mixed coater coating device, which is a main part of the manufacturing method of the present invention, will be described with reference to FIGS. 2 and 3.

In the figure, the same reference numerals as in FIG. 1 indicate the same parts. That is, the coating device is equipped with a roller 17 that rotates via a driving gear 15 and a shaft 16 inside a container made up of a bottom plate 12, two rectangular side plates 13, and two long side plates 14, and when the container is opened. An upper cover plate 18, which also serves as a guide plate for the sealed end face 2 of the funnel 1, is attached to the end edge.

Further, on both sides of the roller 17, a thickness regulating piece 18 and a residue scraping piece 19 of the mixer 4 are attached to a support mechanism 21, respectively.
, 22 to the long side plate 14 in a freely adjustable manner. In the present invention, even when only the roller 17 is used,
The thickness regulating piece 18 and the residue scraping piece 19 are also all referred to as a coating mechanism. The mixture 4 is injected into the coating device 11 having the above structure so that the roller 17 is immersed therein, and when the roller 17 is rotated in the direction of the arrow, the mixture 4 adheres to the roller 17 and rises.

This is scraped off at the tip of the thickness regulating piece 18 so that the mixture film 41 has a predetermined thickness, thereby regulating the amount of the mixture film 41 that adheres to the roller 17 and moves upward. The sealing end surface 2 of the funnel 1 is slightly above the upper part of the roller 17 and is attached to the mixer film 41 by approximately 0.05 Tfr to 0.5 Tfr.
! It is sent along with the support stand 23 from a conveyor (not shown) so that it can be fixed to the extent that it bites into the image. When the funnel comes to rest on the roller 17 coated with the mixer film as shown by the arrow by the suspension device 24 that holds and suspends the funnel, its sealed end surface 2 comes into contact with the mixer film 41.
This film 41 adheres to the sealed end face 2 to form a band-shaped mixture 7, and the excess mixture 42 is removed by the residue scraping piece 19, merges with the lower mixture 4, and goes up the roller again. The rollers described above are made of stainless steel, rubber, or other materials. In the following steps, drying and sealing are performed in the same manner as in the conventional method, so explanations thereof will be omitted.

Even if the thickness regulating piece 18 is not used in the coating device, it is possible to suck up a certain amount of the mixture by regulating the viscosity of the mixer 4, the outer diameter of the roller 17, the rotational speed, etc.; By using it, it can be made even more uniform.

Although it is possible to apply the coating without using the scraping piece 19, if the roller 17 is operated continuously for a long period of time, a hard-to-move mixture layer will remain on the surface of the roller 17, causing the mixture layer to be applied to the sealing end surface 2 of the funnel 1. This may result in a decrease in the amount or local variations in thickness.

Further, if a corner is provided at the opposite end of the scraping piece 19, that is, at the end where the mixer 42 falls, the air bubbles can be pushed out and defoamed there. The rotational speed of the roller 17 is the circumferential speed; more precisely, when the circumferential speed of the mixture at the position corresponding to the sealing surface 2 of the funnel 1 is the same as the feeding speed of the funnel 1, the thickness of the applied mixture is most uniform. become.

In other words, when the circumferential speed is higher than the funnel feeding speed, the sealing surface 2 is fed parallel to the roller 17 on the rear side of the side wall (on the inside for the side to be painted first, and the outside of the funnel for the side to be painted later). There is a disadvantage that the mixture builds up, and conversely, when the circumferential speed is lower than the feed speed of the funnel, the mixture builds up on the front side wall. They become larger as the speed difference increases. In order to reduce the crawling problem, the funnel sealing surface 2 is preferably fed in a diagonal direction with respect to the roller 17 (for example, one side of the sealing end surface 2 is at an angle of 45 degrees with respect to the feeding direction of the funnel). By doing this, there is no side where a large area is coated each time, that is, there is no side that is fed parallel to the roller axis, so there is a place for the mixture to escape. However, if the viscosity is extremely high (e.g. 20,000 poise or more), the content of nitrocellulose should be reduced (e.g. 0.0000 poise in the vehicle).
5%) and the viscosity becomes small, or if the viscosity becomes small due to denitrification during use, it will not be possible to apply it properly. In order to prevent the solvent (e.g. butyl acetate) from volatilizing, it is better to attach a cover or the like to minimize the area in contact with the outside air, that is, the exposed area of the cylinder, and if the solvent becomes too thick due to drying. Evaporated solvent (e.g. butyl acetate)
It is desirable to add and mix before use. The effects of one embodiment of the method for manufacturing a cathode ray tube using the coating apparatus described above are as follows.

1. Since the coating speed is constant, uniform coating is possible.

There is no overlap between the beginning and end of the second coat, so there is no need to worry about wiping it off as it does not overflow.

3. Even if there is a slight change in viscosity, it hardly affects the amount of coating, and adjustment is easy.

4. Application work is extremely simple.

Mixed production of 5 types of tubes is easy.

6 The frit layer can be made as thin as you like.

7. Easy to automate.

The embodiments of the present invention described above are based on the principles, and it goes without saying that the structure and shape of the coating device and coating mechanism can be changed within the scope of the claims, and many other changes in the mechanism and accompanying equipment are also conceivable.

For example, the same effect can be obtained by using a flat plate, a curved plate, etc. instead of the roller 17, and by giving reciprocating motion instead of rotational motion, or by using a belt-shaped mixer carrier. You may. Furthermore, by changing the mechanism, it can be used for a funnel with the sealed end facing upward as shown in Figure 1, and at least one pair of flat display tubes, etc., in which a substrate with a display element on the surface and a bulging cover glass are sealed at the periphery. (Also used when sealing containers)
Of course, it can be used.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional frit glass mixture coating method, Fig. 2 is an explanatory diagram of a main part of an embodiment of the method for manufacturing cathode ray tubes, etc. of the present invention, and Fig. 3 is an explanatory diagram of a method for manufacturing cathode ray tubes, etc. of the present invention. 1 is a partially cutaway perspective view of a coating device adapted to the manufacturing method of FIG. 1... funnel, 4... fritted glass mixer, 11... coating device, 18...
...Thickness regulating piece, 19...Residue scraping piece, 17...Roller, 23...Support stand.

Claims (1)

[Scope of Claims] 1. A step of feeding a second container portion having a sealed end surface that contacts the first container portion into a coating device, and a step of bringing the sealed end surface into contact with a coating mechanism built into the coating device. A method for manufacturing a cathode ray tube or the like, comprising the steps of transferring and coating a fritted glass mixture onto the sealed end surface from the coating mechanism, and sending the second container portion to the next step. 2. The method for manufacturing a cathode ray tube or the like according to claim 1, wherein the coating mechanism is a roller rotating around an axis and having a fritted glass mixture coated on its outer peripheral surface. 3. The fritted glass mixture adhered to the outer peripheral surface of the roller is brought into contact with the sealed end surface of the second container portion after the fritted glass mixture adhered to the outer circumferential surface of the roller is brought into contact with the sealed end surface of the second container portion after being adjusted to a desired thickness by a thickness regulating piece included in the application mechanism. A method for manufacturing a cathode ray tube, etc., according to claim 2. 4. Claim 2, characterized in that the remaining fritted glass mixture coated on the sealed end surface is removed by a roller using a scraping piece included in the coating mechanism.
Method of manufacturing cathode ray tubes, etc. described in Section 1. 5. A method for manufacturing a cathode ray tube or the like according to claim 4, characterized in that the scraping piece is provided with a corner, and the corner is used to crush and defoam air bubbles in the fritted glass mixer. 6. The method for manufacturing a cathode ray tube or the like according to claim 2, wherein the circumferential speed of the roller and the transport speed of the sealed end surface are substantially the same.