JPS6177234A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To check slippage of electrons from their orbits while suppressing electrification of the glass bulb inside by generating discharge plasma around electron guns in a hydrogen gas atmosphere. CONSTITUTION:Electron guns are mounted inside a glass bulb of a cathode-ray tube while being evacuated followed by sealing hydrogen gas for performing discharge. In the discharge plasma in the hydrogen gas hydrogen molecules are excited or ionized while colliding with the inside of the glass bulb near the electron guns. Thereby, a reducing reaction to lead oxide, which is one of main components of the glass bulb, is caused for depositing lead on the glass bulb inside while making said inside to be low-resisting. As a result, the glass bulb inside becomes hard to be electrified thus being able to obtain the cathode-ray tube habing little slippage of the electron beams from their orbits.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing a cathode ray tube for suppressing deviation of electron beam trajectory due to charging of the inner surface of a glass bulb.

[Conventional technology] FIG. 6 is a schematic diagram showing the structure of a general cathode ray tube.

In the figure, (1) is a low voltage electrode (2a), (2b)
, (2c), an electron gun consisting of a focusing electrode (3) and an anode (4), (5) a glass bulb that houses this electron gun (1) and whose interior is kept in a high vacuum, (6) is a conductive film coated on the inner surface of this glass bulb (5), (7) is a high voltage power supply connected to this conductive film (6), and (8) is 1-
A control power source for supplying voltage to the low voltage electrodes (2a), (2b), (2c) and the focusing electrode (3), (
9) is the field emission electron from the high electric field electrode part, (lO)
indicates scattered electrons, and (11) indicates the cathode ray tube body.

Next, the operation will be explained. Low voltage electrode (2a).

Electron beams are generated in parts (2b) and (2c), and their intensity is controlled. The focusing electrode (3) has -
- Converge the electron beam by applying a constant positive voltage and applying a positive high voltage to the positive m (4).

At this time, field emission electrons (8) as shown in FIG. 6 are generated from the ends of the focusing electrode (3) and the low voltage electrode (2c), which produce a high electric field of negative polarity. In addition, part of the electron beam collides with the converging electrode (3) and the anode (4), and the scattered electrons (1
0) also occurs. When these field emission electrons (8) and scattered electrons (10) increase, they collide with the inner surface of the glass bulb (5), charging the inner surface S, and the trajectory of the electron beam is shifted due to this influence. In order to suppress charging of the inner surface of the glass bulb (5), it is necessary to lower the resistivity of the inner surface of the glass bulb.

[Problems to be Solved by the Invention] Incidentally, as shown in FIG. 5, the conventional method for manufacturing a cathode ray tube includes a step A of assembling an electron gun, and a step of mounting the assembled electron gun inside the glass bulb of the cathode ray tube. B. A step of vacuum evacuation of the glass bulb C1. A step F of seasoning by applying a high voltage, and a step G of adjusting and checking the operation. In this method, the resistivity of the inner surface of the glass bulb Since no treatment was applied to stop the glass bulb, it was not possible to suppress the charging on the inner surface of the glass bulb, and it was difficult to suppress the trajectory of the electronic bee J.

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and provides a method for manufacturing a cathode ray tube in which the resistivity of the inner surface of the bulb is reduced to suppress charging of the inner surface of the glass bulb, thereby suppressing deviation of the trajectory of the electron beam. is intended to provide.

[Means for Solving the Problems] This invention involves setting the assembled electron gun in the glass bulb of a cathode ray tube and evacuation, and then introducing hydrogen gas into the galanus bulb described in -1- above. In a hydrogen gas atmosphere] 1) The inner surface of the glass bulb and the electrode surface of the electron gun are treated by generating discharge plasma around the electron gun, and then the inside of the glass bulb 1 is evacuated to vacuum again to remove the electron gun from the glass. It is characterized by being sealed inside the valve.

[Operation] In this invention, excited or ionized hydrogen molecules collide with the inner surface of the glass bulb near the electron gun, and at this time, a reduction reaction occurs with lead oxide, which is one of the main components of the glass bulb. Lead is precipitated on the inner surface of the glass bulb, lowering the resistance of this inner surface and lowering the secondary electron emission coefficient. Furthermore, excited hydrogen molecules and hydrogen ions in the discharge plasma also collide with the electrode, and the kinetic energy at this time drives out impurities on the electrode surface.
A reduction reaction occurs with the second oxide layer to remove the oxide layer and clean the electrode surface.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a manufacturing process for a cathode ray tube according to the present invention. Compared to the conventional device shown in FIG. 5, a step of filling hydrogen gas and performing discharge after evacuation of the glass bulb, and a step E of performing evacuation again after that are newly added.

FIG. 2 shows an example of the process of performing discharge. In the figure, (12) is the cathode ray tube body (
A contactor (11) is used to bring the high voltage terminal into contact with a high voltage line, and (13) is a high voltage power source. By doing this, a high voltage is applied to the cathode ray tube body (11) through the electron gun (
It can be applied to part 1). The applied voltage may be direct current, alternating current, or pulsed.

When high voltage is no longer applied to the electron gun (1), hydrogen gas flows between the anode (4) and the focusing electrode (3), and between the anode (4) and the low-voltage electrodes (2a), (2b), (2c). )
A discharge occurs between the two, producing discharge plasma. In the discharge plasma in hydrogen gas, hydrogen molecules are excited or ionized and collide with the inner surface of the glass bulb near the electron gun (1). At this time, a reduction reaction occurs with lead oxide (PbO), which is one of the main components of the glass bulb (5), and lead (Pb) is deposited on the inner surface of the glass bulb, which has the effect of lowering the resistance of this inner surface. . As a result, the inner surface of the glass bulb (5) is less likely to be charged, so that a highly reliable cathode ray tube with less deviation in the trajectory of the electron beam due to charging can be manufactured.

The cathode ray tube body (11) treated in this way is then evacuated to vacuum again in the glass bulb (5), and the electron gun (+) is sealed inside the glass bulb (5).
be done.

In the above embodiment, high voltage was applied to the anode (4), but the anode (4) was grounded and connected to the converging electrode (3) or the low voltage electrode (2a) through the pin terminal on the low voltage side.
A high voltage may be applied to 2b) and (2c).

FIG. 3 shows another embodiment of the invention.

In this embodiment, a coil (14) is disposed outside the glass bulb close to the electron gun (1), and a high frequency current is supplied to this coil (14) from a high frequency power source (15) to discharge around the electrode. It is designed to generate plasma.

In the case of Fig. 3, a high frequency magnetic field is applied to the electron gun (1), but instead of this, for example, a high frequency electric field from parallel plate electrodes or a high frequency electromagnetic field from a traveling wave tube may be applied. A similar discharge plasma can also be generated.

By the way, although the following explanation focuses on lowering the resistance of the inner surface of the glass bulb, the above method also has the effect of reducing the secondary electron emission coefficient of the inner surface of the glass bulb.

Generally, the secondary electron emission coefficient δ due to electrons of energy E (e'V) incident on the surface exhibits characteristics as shown in FIG. δwax is the maximum secondary electron emission coefficient, Ellaw
is the energy of the incident electron at that time. El and E
2 is the energy when δ=1. The secondary electrification-emission characteristics of lead glass and lead are shown in Table 1. When lead glass is surface-treated with hydrogen plasma, lead precipitates, but as shown in Table 1, the secondary electron emission coefficient of lead is smaller than that of lead glass, so the secondary electron emission coefficient decreases. Electrification on the inner surface of the glass bulb (5) can be suppressed.

As shown in Table 1, in the L distribution method, excited hydrogen molecules and hydrogen ions in the discharge plasma also collide with the electrode.

The kinetic energy at this time drives out impurities on the electrode surface, and also causes a reduction reaction with the oxide layer on the electrode surface to remove the oxide layer and clean the electrode surface. Impurities and oxide layers on the electrode surface cause field emission electrons, and when there are many field emission electrons, it is easy to induce tube discharge, but as the electrode surface of the electron gun is cleaned by discharge plasma, field emission electrons are generated. Since the occurrence of can be suppressed, a highly reliable cathode ray tube with less internal discharge can be manufactured.

[Effects of the invention] Below. According to this invention, as shown in L, the resistivity and secondary electron emission coefficient of the inner surface of the glass bulb are reduced, and the deviation of the electron beam trajectory due to charging can be suppressed, and the electrode surface of the electron gun is also cleaned by the discharge plasma. As a result, impurities and oxide layers that cause field emission electrons are reduced, and as a result, it is possible to provide a highly reliable method of manufacturing a cathode ray tube with less internal discharge.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing process of a cathode ray tube according to the present invention;
FIG. 2 is a diagram showing an example of the process of performing discharge in this invention, FIG. 3 is a diagram showing another example of the process of performing discharge, and FIG. 4 is a diagram showing the energy E of electrons incident on the surface and secondary electron emission. A characteristic diagram showing the relationship with the coefficient δ, FIG. 5 is a diagram showing the manufacturing process of a conventional cathode ray tube, and FIG. 6 is a schematic sectional view showing the structure of a general cathode ray tube. (1)...Electron gun, (5)...Glass bulb, (1
3)...High voltage power supply, (14)...Coil, (15)
...High frequency power supply. Note that the same reference numerals in Figure 1 indicate the same or equivalent parts.

Claims (3)

[Claims] (1) After setting the assembled electron gun inside the glass bulb of the cathode ray tube and evacuation, hydrogen gas is introduced into the glass bulb, and a discharge is made around the electron gun in this hydrogen gas atmosphere. Manufacture of a cathode ray tube characterized in that the inner surface of the glass bulb and the electrode surface of the electron gun are treated by generating plasma, and then the inside of the glass bulb is evacuated again to vacuum and the electron gun is sealed within the glass bulb. Method. (2) A method for manufacturing a cathode ray tube according to claim 1, in which discharge plasma is generated by applying a high voltage to an anode, a focusing electrode, or a low-voltage electrode of an electron gun. (3) The method for manufacturing a cathode ray tube according to claim 1, wherein discharge plasma is generated by applying a high frequency magnetic field or a high frequency electric field to the electron gun from outside the glass bulb.