KR970010042B1 - Electron gun for color picture tube - Google Patents

Abstract

A focus electrode of electron gun used for a color CRT(cathode ray tube) is provided to improve productivity and remove discharging without a horizontal blade. The focus electrode comprises: a focus electrode(6) having a static focus electrode(4) and a dynamic focus electrode(5); and a horizontal blade(10) formed outer part of each electron beam via hole(4a) of the static focus electrode(4), wherein the vertical blade(10) is inserted into the aperture of the dynamic focus electrode(5), such that the vertical blade(10) is not connected to the dynamic focus electrode(5).

Description

Focus electrode of electron gun for color cathode ray tube

1 is a perspective view showing a part of the conventional electron gun cut out.

2 is a longitudinal cross-sectional view of FIG.

3 is a perspective view showing a part of the electron gun of the present invention.

4 is a longitudinal cross-sectional view of FIG.

Figure 5 is a longitudinal sectional view showing another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

4 Static Focus Electrode 5 Dynamic Focus Active

6: focus electrode 10: vertical blade

The present invention relates to a focus electrode of an electron gun for a color cathode ray tube, and more particularly, to obtain better beam characteristics while simplifying the structure thereof.

In general, a color cathode ray tube is provided with a panel having a fluorescent surface inward, a funnel fixed with the panel and having an internal portion, an electron gun encapsulated in the internal portion, and a predetermined distance from the fluorescent surface of the panel, and a myriad of holes formed therein. A shadow mask, an inner conductive film uniformly applied over the neck portion from the inner wall of the panel, an outer conductive film applied to the outside of the funnel, an anode terminal provided at the outer center of the funnel, and a deflection device provided outside the neck portion Consists of

On the other hand, the screen surface applied to the inner surface of the panel is R. G. B phosphors are applied in the form of stripes or dots, so that the three electron beams emitted from the electron gun impact each phosphor selected by the shadow mask to obtain an image.

It also has an electron beam forming unit for generating, accelerating and controlling three electron beams in which the electron gun enclosed in the neck portion is deflected in an in-line array, and a kettle lens unit for focusing and accelerating the electron beam.

However, since the electron beam controlled by the electron beam forming unit and the kettle lens unit passes through the shield cup regardless of the deflecting device, the characteristic of the electron beam deflected by the deflecting device is remarkably different in the central part and the peripheral part.

Accordingly, in order to solve the above problem, a dynamic electrode part having a close relationship with deflection in the electron gun has been formed and used for a long time.

1 is a perspective view of a conventional electron gun partially cut away, wherein the electron gun is a control electrode (Gride electrode) 2 for controlling an electron beam emitted from the cathode 1 and hot electrons gathered on the cathode 1 surface. An acceleration electrode (Screen electrode) 3 to be pulled out and accelerated, a focus electrode 6 composed of a static focus electrode 4 and a dynamic focus electrode 5, and a child forming the focus electrode and the main lens; It consists of the node electrode 7.

The vertical blade 8 is fixed inside the static focus electrode 4 so as to face the dynamic focus electrode 5 between the electron beam passing holes 4a through which the electron beam passes, and the static focus of the dynamic focus electrode 5 is fixed. The horizontal blade 9 is fixed to the upper and lower surfaces on the electrode 4 side so that the horizontal blade 9 is inserted into the static focus electrode 4 at a predetermined interval.

Accordingly, the beam characteristics can be improved at the periphery of the screen by using a change in the front position between the three pairs of vertical blades 8 having the electrostatic potential and the pair of horizontal blades 9 having the equipotential during the operation of the electron gun. do.

However, since the horizontal focusing blade 9 and the vertical blade 8 must be installed separately, the conventional focus electrode has a complicated structure, which increases manufacturing cost and requires two welding processes, resulting in a decrease in productivity.

In addition, in order to increase the strength of the lens in the focus electrode of the structure described above, the length of overlap between the horizontal blade and the vertical blade has to be long, which makes the blade difficult to manufacture and discharges because the blades are close to each other in the wrapping direction. There was a risk of happening.

The present invention has been made to solve the problems of the prior art, without having to install a separate horizontal blade to the top and bottom of the dynamic focus electrode to serve as a horizontal blade to eliminate the risk of discharge and at the same time improve productivity The purpose is to make it possible.

According to an aspect of the present invention for achieving the above object, the focus electrode is divided into a static focus electrode and a dynamic focus electrode in the tube axis direction to apply a constant voltage to the static focus electrode and to apply a dynamic voltage to the dynamic focus electrode. The vertical blade is formed to face the dynamic focus electrode to the outside of each outer beam passing hole of the static focus electrode so that the vertical blade is inserted into a common opening of the dynamic focus electrode so as not to be connected to the dynamic focus electrode. A focus electrode of an electron gun for a colored cathode ray tube is provided.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 3 and 4 of the accompanying drawings.

FIG. 3 is a perspective view showing a part of the electron gun of the present invention, and FIG. 4 is a longitudinal cross-sectional view of FIG. 3, and the same components as those of the conventional electron gun will be omitted and the same reference numerals will be given.

According to the present invention, three electron beam through holes 4a are formed in the static focus electrode 4 of the focus electrode 6 formed in the tube axis direction, and the outer electron beam through holes 4a outside the electron beam through holes 4a. The vertical blade 10 is formed so as to protrude toward the dynamic focus electrode 5. At this time, the vertical blade 10 is installed to be inserted into the common opening of the dynamic focus electrode to a predetermined depth so as not to be connected to the dynamic focus electrode 5 installed on one side.

In one embodiment of the present invention, the vertical blade 10 is configured to have a flat plate shape. However, the vertical blade 10 is formed to be curved as shown in FIG. It may also be formed by (t) lower than the outer portion. As a result, the area of the vertical blade 10 is increased, thereby increasing the potential difference. Referring to the effects of the present invention configured as described above are as follows.

First, in order to improve the characteristics of the electron beam in front of the screen, a constant voltage is applied to the static focus electrode 4 and a parabolic dynamic dynamic voltage is applied to the horizontal and vertical synchronous signals to the dynamic focus electrode 5 so that the electron beam is the two voltage differences. Adjust accordingly.

In other words, when the electron beam emitted from the electron gun is deflected toward the periphery of the screen by the deflector, the astigmatism of the electron beam advances in the negative direction. In order to compensate for this, when the voltage of the dynamic focus electrode 5 is increased, It is formed between the upper and lower surfaces of the vertical blade 10 and the dynamic focus electrode 5 formed outside the outer beam passing hole 4a of the static focus electrode 4 and inserted into the common opening of the dynamic focus electrode 5. The beam is focused in the horizontal direction by the potential difference and the beam is diverged in the vertical direction, thereby preventing the beam characteristic from deteriorating on the periphery of the screen.

In addition, as the voltage of the dynamic focus electrode 5 increases in the dynamic focus electrode 5 and the anode 7, the static convergence position becomes farther away, but compared to the vertical blade 10, the dynamic focus electrode ( Since the voltage of 5) is high, the outer beam at the dynamic focus electrode 5 is slightly focused to the center, thereby suppressing the staggered convergence.

As described above, in the present invention, since the dynamic focus electrode 5 plays the role of the horizontal blade without installing a separate horizontal blade, the number of parts can be reduced compared to the conventional one, thereby reducing the manufacturing cost and reducing the welding process. It is possible to prevent the discharge from occurring by simplifying the opposing surfaces of the vertical blade 10 and the dynamic focus electrode 5.

In addition, since the insertion length of the vertical blade inserted into the dynamic electrode can be easily adjusted and installed, the characteristics of the electrode can be improved.

Claims (4)

The focus electrode 6 is divided into the static focus electrode 4 and the dynamic focus electrode 5 in the tubular direction so that a constant voltage is applied to the static focus electrode 4 and a dynamic voltage is applied to the dynamic focus electrode 5. In this case, the vertical blade 10 is formed to face the dynamic focus electrode 5 outside the outer electron beam passing holes 4a of the static focus electrode 4, so that the vertical blade 10 is a dynamic focus electrode. 5) A focus electrode of an electron gun for a color cathode ray tube, characterized in that a predetermined depth is inserted into a common opening of the dynamic focus electrode so as not to be connected to 5). The focus electrode of the electron gun for color cathode ray tubes according to claim 1, wherein the vertical blades (10) are flat. The focus electrode of the electron gun for color cathode ray tubes according to claim 1, wherein the vertical blades (10) are curved. The focus electrode of the electron gun for color cathode tube according to claim 2 or 3, wherein the upper and lower surfaces of the dynamic focus electrode (5) are formed to be lower than the outer portion by (t), respectively.