JPS5889758A - Manufacture of cathode ray tube - Google Patents

Abstract

PURPOSE:To manufacture a CRT where the electron emission characteristic will never deteriorate for long term, by welding a stem where an electron gun is not yet connected to the end of an already welded neck section and a funnel then inserting the electron gun section into the neck tube and connecting to the stem. CONSTITUTION:A funnel 2 made of glass and a neck tube 3 made of glass are welded previously. The end of a lead 11 of a stem 10a at the inside of the tube is formed while considering the shape, structure and the material such that the connection with each electrode lead of the electron gun section is facilitated, then the stem 10a is welded to the neck tube 3. Thereafter the electron gun section is inserted through an opening of the funnel 2 into the neck tube 3 thus to connect the lead wire of the electron gun electrode with the lead 11. In such a manner a reliable CRT where the electron beam emission is stable for long term can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cathode ray tube that improves cathode life characteristics.

Figure 1 shows a color cathode tube, 1 is a panel, 2 is a funnel, 3 is a neck tube, and 4 is a pulp (
(vacuum envelope), 5 is an electron gun assembly, and 6 is a welded part made of low-melting glass. The conventional manufacturing method for this tube is as follows. A fluorescent surface made of a fluorescent film or a metal back film is formed on the inner surface of a glass panel, and color selection electrodes are further attached inside the fluorescent surface. The present invention is not concerned with these operations, and assumes that the panel 1 is already in this state. Furthermore, the glass funnel 2 and the glass neck tube 3 are welded together in advance.

Further, on the inner surface of the funnel 2, an internal conductive film made of graphite or the like is formed extending toward the entrance of the neck tube 3 (the welding point between the funnel and the neck). On the other hand, the electron gun structure 5
As shown in the figure, there is an electrode assembly 7 in which electrode groups of various shapes are assembled to maintain predetermined relative positions 5, and a lead wire 9 (see Figure 3) is attached to the end of an exhaust pipe 8 as shown in Figure 3. The lower part, that is, the outer side of the tube, serves as a via for connection to the electron gun electrode, and the part that connects the inner lead of the tube to the vial and is embedded in the glass is a circle penetrated by a dimemet wire for sealing the glass. Stem 10 integrally formed with plate glass brim portion
It is constructed by joining. In this case, the inner tube lead of the stem IO and the lead of the electrode assembly 7 are connected by electrical resistance welding or the like, and these leads serve not only for conduction but also for maintaining the relative mechanical position of the electrode assembly 7 and the stem IO. The end face around the opening of the funnel 2 and the end face around the skirt portion of the panel 1, whose inner surfaces have been processed, are welded together using low melting glass (commonly known as frit). This is because it is impossible to form a fluorescent surface of a color cathode ray tube or attach a shadow mask unless the panel and funnel are separated. Generally, the electron gun assembly 5 is inserted into the neck tube from the open end of the neck tube 3 after welding the panel and the funnel, and the neck tube end and the periphery of the stem neck are heated and welded with a gas burner. Now that the vacuum envelope is complete, the next step is to move on to the exhaust work. However, in the conventional manufacturing method, when the stem is newly attached to the end of the neck tube, the glass is at least partially attached to the end of the neck tube. oooca
Since the electrodes of the electrode assembly 7, which are already connected to the stem lead wire 9, also become hot. Therefore, the cathode, which is one of the electrodes and serves as an electron beam emission source, also reaches a high temperature, and the so-called oxide is partly thermally decomposed and even the base metal is oxidized, shortening its life as an electron beam source. was there. This problem occurs not only in color cathode ray tubes but also in other types of cathode ray tubes when a process is adopted in which the stem with the electron gun attached is welded to the neck tube end of the bulb using a gas burner.

An object of the present invention is to provide a method for manufacturing a cathode ray tube that is free from the above-mentioned problems and whose electron emission characteristics do not deteriorate over a long period of time.

In order to achieve the above object, in the present invention, the stem to which the electron gun part is not yet connected is welded to the end of the neck tube that is already welded together with the funnel, and then the electron gun part is inserted into the neck tube from the funnel side opening. We decided to insert it into the tube and connect the lead wires of each part of the electron gun to the lead wires inside the tube of the stem. The alignment or centering of lead wires is
If you use a jig and correct the bends in each lead wire, especially before inserting the electronic sharp part, it will not be #IA*. Connections are best made by resistance welding or lathe, but brazing or fitting (such as so-called connectors) is recommended.
But that's fine. When welding lead wires together, the high-temperature heating area can be confined to a narrow area, and the work can be done in an inert atmosphere, so there is no problem of electrode oxidation. Note that before inserting the electronic sharp part, a conductive film inside the funnel is applied. After completing the connection work between the electron gun and the stem, the panel and funnel are fused together using corresponding frits at the edges to complete the vacuum envelope, and then the exhaust work is performed. Generally, during exhaust work, the part from which gas is to be degassed is heated to a high temperature to increase the pressure of occluded or adsorbed gases, making it easier for these gases to be released.However, each part of the electron gun is cleaned individually! If the electron gun and stem lead are then connected using the method of the present invention while avoiding oxidation of the electron gun electrode, there is no need to heat the electron gun to a high temperature and exhaust it. On the other hand, unlike the electron gun section, the fluorescent surface on the inner surface of the panel and the interior graphite film of the funnel contain moisture and organic components that decompose and vaporize, and are porous, so it is necessary to heat them during exhaust. In such a case, it is desirable to forcibly cool the neck tube to prevent the temperature from rising during passage through the exhaust furnace, especially during the period when the pressure inside the tube is relatively high at the beginning of exhaust, in order to prevent each part of the electron gun from rising.゜Instead of connecting the lead wires, weld a glass disk with an exhaust pipe to the end of the neck tube with holes in each location where the lead wires are to be enclosed, and insert the lead wires from the electron gun side into these holes. The lead wire passing portion may be sealed in vacuum with frit glass. Note that while the temperature during welding work for ordinary glass is about 1.0 OOC, frit glass melts at a temperature of 500 C or less. For the sake of illustration, the funnel, neck tube, and stem welded together just before insertion into the electron gun section is shown in FIG. 4. Generally, some consideration is given to the shape, structure, and/or material of the tube inner tip of the lead 11 of the stem 101 according to the present invention in order to facilitate connection with the electron gun component leads (specifically, , resistance welding, laser welding, or other means (depending on the method employed).

It is preferable to apply similar means to the electrode lead on the electron gun side.

The present invention is applicable not only to color cathode ray tubes, in which the panel and funnel must be welded by the manufacturer of the polar tube due to the necessity of forming a fluorescent surface. It goes without saying that effects can be obtained even if the method is applied to cathode ray tubes other than color tubes to which glass tube manufacturers typically supply pulp.

As explained above, according to the present invention 11+1, a highly reliable cathode ray tube whose electron beam emission is stable over a long period of time can be obtained.

[Brief explanation of drawings]

Fig. 1 shows a color cathode ray tube, Fig. 2 shows an electrode assembly, Fig. 3 shows a stem, and Fig. 4 shows a state in which the funnel, neck tube, and stem are integrally welded according to the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Panel, 2... Funnel, 3... Neck tube, 6... Frit glass welding part, 7... Electrode assembly, 10m... Stem according to the present invention, 11... Pieces Stem lead according to the invention. Agent Patent Attorney Susuki 1) Toshiyuki 1 Figure 2 Figure 1 /1

Claims (1)

[Claims] After welding the connecting bottle and the comparatively short lead wire inside the tube that communicates with these to the end of the neck tube that is integrally welded to the funnel, insert it into the neck tube from the opening on the funnel side where the electron gun is. A cathode ray tube characterized in that the lead wire of the electron gun part electrode is inserted into the stem and connected to the lead wire injected into the stem, and finally the panel and funnel are welded to complete a vacuum envelope. manufacturing method.