JPS6054138A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent any reverse processes of ageing which might be caused by field discharge from a high potential electrode constituting a main focusing lens, by performing high voltage ageing of low potential electrodes while maintaining the high potential electrode and a focusing electrode facing the high potential electrode at the same electric potential by connecting them outside the tube. CONSTITUTION:A focus electrode 13 and an anode 14 are both connected to the high-voltage terminal 10a of an ageing high-voltage power source 10 and are maintained at the same electric potential. The other terminal 10b of the power source 10 is etched. G1, G2 and G4 low potential electrodes 15 are connected together and earthed. Since the anode 14 and the focus electrode 13 are connected outside the tube and have the same electric potential, any unnecessary field discharge does not occur and no reverse processes are caused. As a result, the desired voltage-resistant quality can be obtained in a very short time without any necessity of performing reageing or the like, without causing any damage to the surface of the focus electrode 13.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to a high voltage aging method for cathode ray tubes.

[Technical background of the invention]

In the manufacture of cathode ray tubes, in which an electron gun is sealed in glass pulp and subjected to emission aging, small protrusions and necks on the electrode surface inside the tube are removed (contaminants on the inner surface are removed, and internal discharges and electric fields are removed. In order to prevent radiation, so-called high-voltage aging using spot knocking, induction coils, etc. is performed.

Field emission (hereinafter referred to as FB) due to field emission in a cathode ray tube is generated from the focus electrode part due to the anode potential, and the other is generated from the cathode equivalent part below the focus electrode (called the low electrode part) due to the focus potential. ) are broadly classified into those that occur.

Currently, industrially, a combination of the following high voltage aging methods is used. The first process for FE using the anode potential is to
This is a method of applying a voltage ~3 times as high as the aging process between the high-voltage opposing electrodes, and for FB from the low electrode part due to the focus potential, directly
This is a method of applying ~3 times the voltage.

[Problems with background technology]

When performing high-voltage aging by combining the above-mentioned high-voltage processing methods, there is a known drawback that there is a contradiction in that the FB from the focus electrode due to the anode potential deteriorates after the low-electrode processing. For this reason, there are industrial problems such as having to perform high voltage aging several times in combination.

The reason for this is explained using a pi-potential electron gun as shown in Figure 1, where a potential 2 to 3 times the focus voltage is directly applied to the focus electrode in the low electrode processing process.
Electrons (3), which are attracted by the high electric field (HV) applied to the focus electrode (1) from a high-voltage aging power supply and are emitted from the anode (2) surface by field emission, collide with the focus electrode surface, causing skin to appear on the surface. Causes rough damage.

The cause was found to be the so-called reverse aging process. The wiring between the electrode and the aging power source in the aging process shown in FIG. 2 is shown.

[Purpose of the invention]

The present invention improves upon the conventional aging methods described above and provides a high voltage aging method that provides effective processing quality without incurring reverse processes.

[Summary of the invention]

The method for manufacturing a cathode ray tube according to the present invention relates to a high-pressure aging method for low-potential electrodes, in which a high-potential side electrode forming a main focusing lens and a focus electrode facing thereto are connected outside the tube so that both electrodes are at the same potential. It is characterized by performing high-pressure aging on the low-potential electrode while holding the high-potential electrode, and prevents field emission from the high-potential electrode to prevent the reverse process of aging from occurring.

[Embodiments of the invention]

The present invention will be explained below with reference to one embodiment of a cathode ray tube having a multistage focusing electron gun. In the wiring diagram shown in Fig. 3, αυ is a cathode ray tube with the heater omitted;
This contact piece reaches the power supply rail (13b)
is connected to. Further, the anode I is connected to an anode contact piece (14a) by wiring, as with the focus electrode, and this contact piece is connected to a power supply rail (14b). Furthermore, both of the power supply rails (13b) and (14
b) are both connected to the high voltage terminal (10a) of the aging high voltage power supply (10) and held at the same potential. Note that the other terminal (10b) of the power source θ0) is grounded.

In addition, the low electrodes of G connected and this feed rail is grounded.

As mentioned above, aging is achieved by short-circuiting the focus electrode and the anode via the power supply rail outside the tube, and in addition, all the static It is applicable to all cathode ray tubes that employ an electrofocusing electron gun.

〔Effect of the invention〕

According to this invention, during high-voltage aging of a low-potential electrode, the anode and focus electrode are connected (short-circuited) outside the tube, so they are at the same potential and there is no unnecessary field emission and no reverse process occurs. . As a result, the desired withstand voltage quality of J9 can be obtained in an extremely short time without damaging the surface of the focus electrode and without the need for re-aging.

[Brief explanation of drawings]

Figure 1 is a schematic diagram explaining conventional aging;
FIG. 3 is a wiring diagram showing a conventional aging method, and FIG. 3 is a wiring diagram showing an aging method according to an embodiment of the present invention. 11... Cathode ray tube, 13... Focus electrode 13a
11.4a, i5a... Contact piece 14...
・Anode, 10... Aging high voltage power supply, 13b,
14b, 15b... Power supply rail agent Patent attorney Inoue - Male Figure 1 Figure 2 Figure 3ffl

Claims (1)

[Claims] In high-voltage aging of the low-potential electrode of a cathode ray tube, the high-potential side electrode that forms the main focusing lens and the opposing focus electrode are connected outside the tube and both electrodes are held at the same potential to perform high-voltage aging. A method for manufacturing a cathode ray tube, characterized in that: