JPS63110523A - Treatment of electron gun - Google Patents

Abstract

PURPOSE:To prevent potential fluctuation caused by current leakage by irradiating electron beams from a cathode of an electron gun to an electrostatic convergence electrode and the periphery thereof so as to eliminate the source of current leakage in the periphery of the electrostatic convergence electrode. CONSTITUTION:The irradiation of electron beams from a cathode of an electron gun 2 to the periphery of an electrostatic convergence electrode 3 causes electrons to collide with electrostatic convergence electrode plates 3c and 3d, resulting in decreased potential of the electrostatic convergence electrode plates 3c and 3d, and increased potential difference, i.e. convergence potential difference Econv, between the electrostatic convergence electrode plates 3c and 3d and high tension electrode plates 3a and 3b. The increased convergence potential difference Econv provides actual knocking effect, eliminating dusts and hurrs. At the same time, the irradiation of electron beams causes the electrostatic convergence electrode 3 and peripheral electrodes to generate heat and discharge the gas absorbed to the electrodes, and the electron collision, too, causes the gas absorbed to the electrodes to discharge, with the discharge gas absorbed to a getter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of processing an electron gun to stabilize the electrostatic concentration characteristics of a cathode ray tube.

[Summary of the invention]

The present invention provides an electrostatic concentration type electron gun for a cathode ray tube, in which the electrostatic concentration electrode and its surrounding electrodes are irradiated with an electron beam from the cathode of the electron gun, thereby increasing the electrostatic concentration voltage and reducing heat generation of the electrode. This interaction eliminates electrical leakage sources around the electrostatic concentrating electrode, prevents voltage fluctuations at the electrostatic concentrating electrode, and stabilizes the electrostatic concentrating characteristics of the cathode ray tube.

[Conventional technology]

In color cathode ray tubes, there are two methods for concentrating the electron beam on the fluorescent surface: an electromagnetic concentration method and an electrostatic concentration method.

The latter electrostatic concentration method is used in color cathode ray tubes based on the Trinitron (registered trademark) method. That-
An example is shown in FIG.

In the figure, (1) shows a tube, and (2) shows an electron gun disposed inside the neck (1a) of the tube (1). The electron gun (2) has, for example, three cathodes KRI corresponding to red, green and blue.
The first grid G1, the second grid G2, the third grid G3, and the fourth grid G4 are commonly used for Ka + Ks.
and a fifth grid G5 are arranged in unipotential type or pi potential type, and the fifth grid G5
Electrostatic convergence means (so-called electrostatic concentration electrode) (3) is arranged after the electrostatic convergence means (5).

The electrostatic convergence means (3) includes opposing inner deflection electrodes (so-called high voltage electrode plates) (3a) and (3b).
and outer deflection electrode plates (so-called electrostatic collecting electrode plates) (3c) and (3d) on the outside thereof.

The inner deflection electrode plates (3a) and (3b) are the fifth grid G.
5, to which an anode voltage HV is applied, and a convergence voltage CV lower than the anode voltage HV to the outer deflection electrode plates (3C) and (3d).

The potential between the inner deflection electrode plates (3a) (3b) and the outer deflection electrode plates (3c) (3a) is 1.5 to 2. O
A potential difference of KV is given. The anode voltage HV and the convergence voltage C■ can be applied by supplying both the anode voltage HV and the convergence voltage C■ from an anode button (not shown) using a coaxial cable, and by supplying the anode voltage HV from a 7-node button. There is a method in which the convergence voltage CV is supplied by a dividing resistor plate built inside the cathode ray tube.

Figure 9 shows the former method of supplying by coaxial cable.As shown in the figure, the center conductor (7) of the coaxial cable (6)
) is connected to the outer deflection electrode plate (3C) to give a convergence voltage CV, and a C-shaped metal plate spring (9) connected to the outer conductor (8) is connected to the funnel part (1b).
The conductive contact (10) from the fifth grid G5 contacts the end of the internal conductive film (4) in the neck part (1a). The anode voltage II V is applied by elastically contacting the part.

Figure 10 shows the convergence voltage C at the latter dividing resistor plate.
This is a method of supplying V. In the same figure, parts corresponding to those in FIG.
11) shows a divided resistance plate, in which a resistance path (13) is printed on the - side of an insulating substrate (12) made of ceramic or the like, and terminals jl are connected to both ends of the resistance path (13) and a predetermined intermediate part, respectively.
+ Constructed by forming t2 and L3. (14) is a protective coating that is applied as necessary. This divided resistance plate (11) is arranged on the side surface of the first grid G1 to the fifth grid G5, and its terminal t2 is a terminal bin (
15), the terminal t1 is connected to the fifth grid G5 of the anode voltage.
The intermediate terminal t3 is connected to the outer deflection electrode plates (3c) and (3d) of the convergence means (3), from which a convergence voltage C■ is applied.

[Problem that the invention seeks to solve]

As mentioned above, in the electrostatic concentration type cathode ray tube, the deflection electrode plates (3a) to (3d) are incorporated as part of the electron gun electrode in order to concentrate the electron beam in the horizontal direction, and the inner deflection electrode plate There is a potential difference of 1.5 to 2.0 KV between the outer deflection electrode plates (3a) and (3b) and the outer deflection electrode plates (3c and 3d). For this reason, if some cause acts around the deflection electrode plate and there is electrical leakage, it causes a potential change between the inner and outer deflection electrode plates, which causes a quality deterioration of the concentration characteristics of the electron beam on the fluorescent surface. In the completed cathode ray tube, horizontal static convergence change occurs, which is a serious drawback as a cathode ray tube.

As a means to eliminate this drawback, for cathode ray tubes in which the convergence voltage C■ shown in Fig. 9 is applied through the anode button, a method is taken to apply a high voltage from outside the tube body through the anode button to perform non-king processing. . However, there is a divided resistance plate (11) inside the tube in Figure 10.
There has been no improvement in cathode ray tubes that incorporate a convergence voltage CV and apply a convergence voltage CV.

In view of the above-mentioned points, the present invention provides an electron gun processing method that can stabilize the electrostatic concentration characteristics in a cathode ray tube regardless of the voltage application method to the electrostatic concentration electrode.

[Means for solving problems]

The present invention provides an electrostatic concentrating electron gun (2) that integrally has an electrostatic concentrating electrode (3) built into a cathode ray tube. The electrode (3) and its surrounding electrodes are irradiated.

In this case, the electron beam taken out from the cathode K of the electron gun (2) is electrostatically concentrated from the fifth grid G5 by simultaneous alternating deflection in both vertical and horizontal directions, or by alternating deflection in one direction (for example, vertical direction). Irradiates the area around the electrode for a certain period of time. The amount of current taken out from the cathode needs to take into account the knocking effect and the heating effect of the electrode, which will be described later, so the total amount of current is Σlk=0.5 to 2. A range of OmA is preferable, and the current amount and irradiation time are set so as not to cause side effects on the cathode characteristics (emission reduction due to adsorption of gas released by the electron beam on the internal conductive film to the cathode). Further, if ΣIk is 0.9 mA or more, the above effect can be obtained with short-time irradiation (20 seconds to 30 seconds). An electromagnetic deflection means (21) or a quadrupole coil (22) can be used as a beam deflection means for irradiating the electrostatic concentration electrode (3) and its surrounding electrodes with an electron beam. This beam deflection means is disposed between the electrostatic concentrating electrode (3) and the cathode of the electron gun, and for example, in the case of the electromagnetic deflection means (21), it is disposed at a position retreated from its normal position toward the cathode. Furthermore, in Kenpo, electron beam irradiation is performed under conditions such that the electrostatic concentrated electrode electric field (i.e., convergence potential difference) during the deflection operation is higher than the steady operating state of the cathode ray tube.

[Effect]

In an electrostatic concentrating electron gun, electric leakage around the electrostatic concentrating electrode is thought to be caused by the particles of the electrode, dust attached to the electrode, and gas adsorbed by the electrode.

In Kenpo, by irradiating the electron beam from the cathode of the electron gun (2) around the electrostatic concentration electrode, the electrons collide with the electrostatic concentration electrode plates (3c) and (3d), resulting in electrostatic concentration. The potential of the electrode plates (3c), (3d) becomes low, and the electrostatic concentration electrode plates (3c), (3
d) and the high-voltage electrode plates (3a) and (3b), that is, the so-called convergence potential difference Econv increases. This is proven by the equivalent circuit diagram in Figure 8 (
Ri.

R2 and R3 are the resistance values of the path through which the electron beam flows). This convergence potential difference E conv
By increasing the size, a substantial knocking effect is obtained and dirt and debris are removed. At the same time, the electrostatic concentrating electrode (3) and the surrounding electrodes generate heat due to electron beam irradiation, and the gas adsorbed on the electrodes is released, and the gas adsorbed on the electrodes is also released due to the collision with the electron beam. be done. The released gas is adsorbed by the getter. In this way, the interaction of the increase in convergence potential difference caused by electron beam irradiation, the heat generation of the electrode, and the collision of electrons ensures that the source of electrical leakage in and around the electrostatic concentration electrode (3) disappears more reliably. achieved. Therefore, potential fluctuations caused by electrical leakage around the electrostatic concentration electrode are prevented, and the electrostatic concentration characteristics are stabilized.

[Example] Example 1 This example is a case where electromagnetic deflection means is used as the electron beam deflection means. In a cathode ray tube of the type shown in Fig. 10 that incorporates a dividing resistor plate (11) and applies a convergence voltage, the setting position of the electromagnetic deflection means (21) (see Fig. 3) is set back from the normal setting position. The electron beam from the cathode of the electron gun (2) is transferred to the convergence means (3) and its surrounding electrodes (for example, the fifth grid G5).
, fifth grid G5 and inner deflection electrode (3a), (
The pole piece (16)') between 3b) is irradiated.

Figure 1 shows the change in convergence potential, 1Econv, between the inner deflection electrode plates (3a), (3b) and the outer deflection electrode plates (3c), (3d) when the setting position of the electromagnetic deflection means (21) is changed. As shown, this test condition is
Anode voltage HV = 25.5K V, second grid G2 voltage EC2 = EC2CO%, fourth grid G4 voltage EC4 = 133V, total amount of current taken out from the cathode ΣIk = ABL (automatic beam limiter: maximum average current Item) Conditions [Red = 540IIA.

Green = 410 μA, Blue = 350 μA], beam irradiation time 3
0 seconds, and the current applied to the electromagnetic deflection means was the same as the normal cathode ray tube operating conditions. According to FIG. 1, it can be seen that the convergence potential difference E conv becomes larger than the convergence potential difference B conv-1,97 at the normal operating position depending on the set position of the electromagnetic deflection means (21). Furthermore, as shown in Fig. 3, the electromagnetic deflection means (21) is set to a position 65 mm backward from the normal position, and the convergence potential difference E conv and the total amount of current ΣIk (here, the red, green, and blue currents are Figure 2 shows the relationship between (with equal amounts).

Figure 4 shows the movement position of the deflection center when the electromagnetic deflection means (21) is retracted, and shows the deflection center of the beam when the electromagnetic deflection means is moved back 65 mm from the beam deflection center x1 at the regular electromagnetic deflection means position. x2 moves into the fifth grid G5.

According to FIG. 2, it is recognized that as ΣIk becomes thicker, the convergence potential 1Econν becomes larger.

Table 1 shows an example of the convergence potential difference E con4 when the moving amount d of the electromagnetic deflection means (21) is 65 mm.

Table 1 Example 2 This example is a case where a quadrupole coil is used as the electron beam irradiation means. As in Embodiment 1, for a cathode ray tube that incorporates the dividing resistor plate (11) shown in FIG. 10 and applies a convergence voltage, as shown in FIG. quadrupole coil (2
2), and the convergence means (3) and its surrounding electrodes are irradiated with an electron beam from the cathode of the electron gun (2). FIG. 5 shows the appearance of the four positive pole coil.

When this four-positive coil (22) is used, the convergence potential difference E C0nV changes depending on ΣIk and the current applied to the four-positive coil (22).

Figure 7 shows this situation, where curve (1) is ΣIk-
For 540μA (red only), the curve (I[) is ΣI
When k = 600 μA (200 μA each for red, green, and blue), the curve (III) corresponds to the ΣIk = ABL condition (red = 540 μA).
Curve (IV) is for Σlk=410μ^ (green only). This test condition is anode voltage HV=25.5K
V, the second grid G4 voltage EC2=EC2CO%, the fourth grid G4 voltage Ec4=133 V, and the beam irradiation time was 30 seconds. The actual measured values in Figure 7 are quadrupole coil (22
) when current is applied only to the horizontal deflection coil. The number of turns of the coil was 200 turns.

Table 2 shows ΣIk=ABL conditions (red - 540 μA, green = 41
0 μA, blue = 350 μ^) and the current applied to the four positive electrode coils is 500 mA.

Table 2 Looking at the quadrupole coil input current, when an alternating current of 60 (fiz) is applied to the vertical deflection coil and the horizontal deflection coil input current is 0, around the deflection electrode plate of the electrostatic convergence means, The electrical leakage improvement rate was around 30%, but the improvement rate of 100% was ensured by injecting a rectangular wave or direct current to the horizontal deflection coil.

From the test results of Examples, the electron gun processing method shown in Examples 1 and 2 showed a 100% improvement in electrical leakage around the electrostatic convergence means.

In addition, the upper part was applied to a cathode ray tube with a built-in dividing resistor plate,
The present invention is also applicable to other cathode ray tubes in which the anode voltage HV and convergence voltage C■ are supplied from the anode button through a coaxial cable.

〔Effect of the invention〕

According to the present invention, in an electrostatic concentrating electron gun, by irradiating the electrostatic concentrating electrode and its surroundings with an electron beam emitted from the cathode of the electron gun, the source of electric leakage around the electrostatic concentrating electrode disappears. Potential fluctuations caused by electrical leakage can be prevented. Therefore, the electrostatic concentration characteristics can be stabilized more reliably than the conventional knocking method.

In color cathode ray tubes, horizontal static convergence change characteristics are improved, resulting in improved image quality.

In addition, the true nature is that it can be easily made without complicating the manufacturing process,
It becomes possible to apply the electrostatic concentration method to cathode ray tubes regardless of the voltage application method to the electrostatic concentration electrode.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the amount of movement of the electromagnetic deflection means and the convergence potential difference, which is used to explain the present invention, FIG. 2 is a graph showing the relationship between the amount of current ΣIk and the convergence potential difference, and FIG. 3 is an example of the present invention. 4 is a side view of the cathode ray tube showing the retracted position of the electromagnetic deflection means, FIG. 4 is a side view of the essential parts of the electron gun showing the deflection center position when the electromagnetic deflection means is retracted, and FIG. 5 is a side view of another embodiment of the present invention. A perspective view of a quadrupole coil used in the example, FIG. 6 is a side view of a cathode ray tube showing a state in which quadrupole coils are arranged in another embodiment of the present invention, and FIG. 7 is an input current to the four positive electrode coils. Figure 8 is an equivalent circuit diagram of a cathode ray tube. Figure 9 is a graph showing the relationship between
The figure is a cross-sectional view of an example of a cathode ray tube of an electrostatic concentration type, and FIG. 10 is a cross-sectional view of a main part of another example of a cathode ray tube of an electrostatic concentration type. (11 is a tube body, (2) is an electron gun, (3) is an electrostatic convergence means, (21) is an electromagnetic deflection means, and (22) is a four-positive coil.

Claims (1)

[Claims] An electrostatic concentrating electron gun incorporated in a cathode ray tube is characterized by irradiating an electrostatic concentrating electrode and its surroundings with an electron beam from the electron gun to stabilize the potential of the electrostatic concentrating electrode. Electron gun processing method.