KR940005494B1 - Electron gun for c-crt - Google Patents

Abstract

The electron gun in which a quadrupole lens having first and second electrodes is disposed between focus electrodes, a focus static voltage is applied to th focus electrode and the first electrode of the quadrupole lens, a dynamic voltage is applied to the second electrode, an electrode piece to be disposed at the center of the beam passing hole is attached to the first electrode of the quadrupole lens, and an electrode piece to be disposed at the top and bottom of the beam passing hole is attached to the second electrode, thereby horizontally elongating the electron beam on the periphery of the tube.

Description

Color gun

1a and b are diagrams showing that three electron beams of red (R), green (G) and blue (B) are deflected by a pincushion magnetic field which is a horizontal deflection magnetic field and a barrel magnetic field which is a vertical deflection magnetic field. Degree.

2A and 2B are explanatory diagrams showing that the electron beam is horizontally stretched by a pincushion magnetic field and a barrel magnetic field.

3A and 3B are explanatory views showing a cross sectional view showing a conventional electron gun and a beam split phenomenon on a screen;

4 is a cross-sectional view of the present invention residual gun.

5A and 5B are a perspective view and a front view showing a first electrode of a quadrupole lens configuration electrode constituting the quadrupole lens of the electron gun of the present invention;

6A and 6B are a perspective view and a front view showing a second electrode of a quadrupole electrode construction pole;

FIG. 7 is a perspective view showing a coupling state between a first electrode and a second electrode of the quadrupole lens configuration electrode shown in FIGS. 5 and 6;

8A and 8B are explanatory diagrams showing a deflection field effect of an electron beam by the electron gun of the present invention.

9 is an explanatory view showing the configuration of the quadrupole lens of the electron gun of the present invention.

10 is a waveform diagram showing a relationship between a deflection current and a dynamic focus voltage.

Figure 11 is a shape of the beam spot implemented on the screen by the electron gun of the present invention.

12 is a cross-sectional view similar to FIG. 4 showing another embodiment of the present invention.

＊ Explanation of symbols on main parts of drawing

23: focus electrode 23A, 23B: focus electrode part

25: quadrupole lens configuration electrode 25A: first electrode

25B: second electrode 26, 27: electrode piece

28, 30: beam through hole.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electron gun for color receivers used in large-sized televisions or high-definition monitors, and more particularly to an electron gun for color receivers in which resolution deterioration is improved at the periphery of the screen of the receiver.

In general, as shown in FIG. 1, three electron beams of red (R), green (G), and blue (B) are automatically concentrated in the entire screen by an inline self-convergence magnetic field. The Convergence field consists of a pincushion field, a horizontal deflection field, as shown in FIG. 1a, and a barrel field, a vertical deflection field, as shown in FIG. 1b, which is composed of two and four main components, respectively, as shown in FIG. The electron beam 10 emitted from the electron gun is directed toward the dashed arrow direction by the bipolar component, and is subjected to magnetic force in the dashed arrow direction by the microelement 4 to diverge in the horizontal direction and to receive the focusing force in the vertical direction. As shown by the sign 11, it is enlarged.

Therefore, astigmatism occurs in the electron beam spot, especially at the periphery of the screen, which causes the imaging planes of the electron beam to be different from each other in the vertical and horizontal directions so that the electron beam spot becomes over-focus on the fluorescent surface. Due to the distance difference, the over-focus is intensified in the periphery of the screen, and the resolution deterioration in the periphery is very severe.

3a shows a conventional electron gun, which is composed of a cathode 12, a control electrode 13, an acceleration electrode 14, a focus electrode 15, and an anode 16, and each of the electrodes 13-16. ), All three electron beam passing holes of red (R), green (G), and blue (B) are circular.

Only the focus constant voltage is applied to the focus electrode 15.

3b shows a beam spot shape implemented on the screen by the electron gun of the prior art. In particular, a haze (h) is severely generated around the electron beam spot in the periphery of the screen.

The conventional electron gun, as shown in FIG. 3A, has a cathode 12, a control electrode 13, an acceleration electrode 14, a focus electrode 15, and an anode 16 on a bead glass (not shown). Exposed at regular intervals, the control electrode 13 controls the electron beam amount of the hot electrons emitted from the cathode 12 and the acceleration electrode 14 accelerates it.

The accelerated electrons are focused on the fluorescent surface by the focus electrode 15 and the anode 16 constituting the main lens to generate a pixel. A voltage of about 300-500 V is applied to the acceleration electrode 14, and the anode 16 is applied to the anode 16. Depending on the model, a high pressure of about 20-27 KV is applied.

The electron gun of the prior art has a good focus characteristic at the center of the screen by the self-convergence magnetic field of the deflection yoke mounted outside the receiving tube of the electron beam, but is subjected to deflection aberration in uneven magnetic field as shown in FIG. Uniformity is lowered and astigmatism occurs, and as shown in FIG. 3B, the resolution at the peripheral portion is degraded.

This tendency is intensified as the deflection angle increases and the water pipe becomes larger.

In other words, the cross section of the electron beam is distorted according to the deflection of the electron beam, and as shown in FIG. 3B, the beam spot is vertically extended with the elliptical high luminance core (C) long in the horizontal direction and the power spot in the central portion and the vertical direction. With (H), the resolution inevitably deteriorates in the periphery of the screen.

Therefore, the deflection yoke of the electron beam spot provides a non-uniform magnetic field as shown in FIG. 1 with respect to the three electron beams, thereby enhancing the horizontal direction of the electron beam in the deflection magnetic field. The distortion of the electron beam due to the non-uniform deflection magnetic field should be compensated for, and the gap caused by the distance difference from the electron gun to the center and periphery of the screen should be compensated for the change of focus voltage.

The present invention has been made to solve the drawbacks of the prior art electron gun, and the object of the present invention is to improve the degradation of the resolution at the periphery of the screen of the receiving tube, which is described in more detail based on FIG. The explanation is as follows.

In FIG. 4, the electron gun is composed of a cathode 20, a control electrode 21, an acceleration electrode 22, a focus electrode 23, and an anode 24, which are mounted on a pair of bead glass (not shown). Are arranged in line.

According to the present invention, the focus electrode 23 is divided into two focus electrode portions 23A and 23B, and a quadrupole lens configuration electrode 25 (hereinafter referred to as four-pole electron) between the focus electrode portions 23A and 23B. Is excreted. The quadrupole electrode 25 disposed between the two focus electrodes 23A and 23B is composed of a first electrode 25A and a second electrode 25B.

Electrode pieces 26 and 27 for constituting a quadrupole lens around the beam passing hole are welded and attached to these electrodes 25A and 25B as will be described later in detail.

As shown in FIGS. 5A and 5B, the first electrode 25A of the quadrupole electrode 25 has three beam through holes 28 and is parallel to a line extending the centerline of each beam through hole 28. An electrode piece 26 having a width having a size of 1/2 to a diameter size of the beam passing hole 28 is attached. As a result, the electrode piece 26 is attached in a form separated by three beam passing holes 28 at the center of the first electrode 25A.

On the other hand, the second electrode 25B of the quadrupole electrode 25 is an electrode piece 26 of the first electrode 25A above and below the three beam through holes 29 as shown in Figs. 6A and 6B. ) Is attached to the compensating shape and the electrode piece 27. As a result, the electrode pieces 27 are separated from each other up and down.

The first and second electrodes 25A and 25B of these quadrupole electrodes 25 are complementarily coupled to each other in a state where the respective electrode pieces 26 and 27 face each other, and the combined state thereof is seventh. As shown in the figure.

In this state, the gap between the opposing surfaces of the first and second electrodes 25A and 25B and the coupling sides of the electrode pieces 26 and 27 is maintained at about 0.6 to 1.0 mm. 26) (27) should be relatively thick.

The quadrupole electrode 25 composed of the first electrode 25A and the second electrode 25B is disposed between the focus electrode portions 23A and 23B, and these constitute the focus electrode as a whole.

On the other hand, as shown in FIG. 4, in the electron gun of the present invention, the electron beam leaving the cathode 20 is accelerated by the accelerating electrode 22 via the control electrode 21. Then, the focus electrode 23 and the anode 24 generate pixels on the fluorescent surface.

In the present invention, the focus constant voltage Vsf is applied to one focus electrode part 23A, the other focus electrode part 23B of the focus electrode 23, and the first electrode 25A of the quadrupole electrode 25 and the four-pole electrode. 25, the second electrode 25B becomes the focus dynamic voltage VDf.

As in the other embodiment shown in FIG. 12, the first electrode 25A of the quadrupole electrode 25 is attached to the focus electrode portion 23A, a constant voltage is applied to the focus electrode 23, and a dynamic voltage is applied to the second electrode. Can be authorized. The dynamic focus voltage changes the waveform of the focus voltage according to the CDT phosphor surface factor, but in most cases, the parabolic waveform is supplied so that the dynamic focus voltage is applied.

As shown in FIG. 10, the focus voltage changes to a parabolic waveform according to the deflection current of the deflection yoke. The dynamic focus voltage is generally set such that Vsf ± 300V _pp or Vsf ± 600V _pp is applied.

The electron beam emitted from the cathode 20 passes through the control electrode 21 and the acceleration electrode 22 and passes through the focus electrode portion 23A of the focus electrode 23 and the first electrode 25A of the quadrupole electrode 25. . As the parabolic waveform passes through the second electrode 25B of the quadrupole electrode 25, the electron beam appears in an elongated shape as shown in FIG.

Parabolic waveforms apply a higher voltage toward the periphery, so the longer the electron beam, the larger the periphery. And this is laterally enlarged at the periphery by the deflection magnetic field so that the focus characteristic of the periphery becomes good as shown in FIG.

Claims (1)

Consisting of the cathode 20, the control electrode 21, the acceleration electrode 22, the focus electrode 23 and the anode 24, from which the electron beam is emitted, the focus electrode 23 is attached to the focus electrode portion 23A. And the quadrupole lens configuration electrode 25 composed of the first electrode 25A and the second electrode 25B between the focus electrode portions 23A and 23B. The focus constant voltage is applied to the first electrode 25A of the 23A and 23B and the quadrupole lens configuration electrode 25, and the dynamic voltage is applied to the second electrode 25B, and the quadrupole lens configuration electrode 25 is applied. An electrode piece 26 disposed at the center of the beam through hole 28 is attached to the first electrode 25A, and an electrode piece 27 is provided on the upper and lower sides of the beam through hole 29 to the second electrode 25B. An electron gun for a color image tube, characterized in that each of the electrode pieces (26) (27) constitutes a quadrupole lens around a beam through hole (28) (29) which is attached and coincides.