JPH0129300B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a color picture tube equipped with an in-line three-beam electron gun.

FIG. 1 shows an in-line three-beam electron gun in a conventional color picture tube. In the figure, 1 indicates three cathodes arranged in a row, and 2 indicates each of the cathodes 1 and 2.
Three electron beam passing holes 201, 20 corresponding to
3 is a first grid electrode having electron beam passing holes 301, 302, 303; 4, 5 are focus electrodes; 401, 40 are focus electrodes;
2,403 is an electron beam passing hole formed in the focus electrode 4. These cathodes 1 and each electrode 2~
5 and the like are integrally supported by a pair of insulating supports (not shown) to constitute an in-line three-beam electron gun M.

In the above configuration, the electron beam emitted from the cathode 1 passes through the electron beam passing hole 20 of the first grid electrode 2.
1 to 203 and the electron beam passing holes 301 to 303 of the second grid electrode 3, the electron beam is focused by an electron lens constituted by focus electrodes 4 and 5, and is focused on the fluorescent surface of the color picture tube (not shown). image is formed.

FIG. 2 is a partially enlarged sectional view of a second grid electrode 3 and a focus electrode 4 of a conventional electron gun.

In the figure, when considering the trajectories of three electron beams a ₁ , a ₂ , and a ₃ , the center electron beam a ₂ has electrodes 3 and 4 arranged symmetrically with respect to the electron beam a ₂ . Because of this, the electron beams a ₁ and a ₃ on both sides travel straight along the center line b ₂ as shown in the figure, but the electrodes 3 and 4 are asymmetrical with respect to each of the electron beams a ₁ and a ₃ . The center line b ₁ of the electron beam passing holes 301 and 401 is
In addition, the electron beams 303 and 403 are each bent inward from the center line b ₃ . This means that the electron beams a ₁ and a ₃ then pass off the center of the electron lens composed of the focus electrodes 4 and 5, and therefore the electron beams a ₁ and a ₃ are distorted due to the aberration of the electron lens. The light reaches the fluorescent surface in a state that is not clear, and this reduces the resolution of the picture tube.

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and the electron beam passing through the electron beam passing holes on both sides of the electron gun is configured to pass along the center line of the passing holes, thereby improving the resolution. The purpose of this project is to provide a color picture tube that can achieve

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows the main parts of the electron gun applied to the color picture tube according to the present invention, and the same parts as in FIG. 2 are given the same reference numerals and the explanation thereof will be omitted.

In the same figure, plane parts 31 and 33 having electron beam passing holes 301 and 303 on both sides of the second grid electrode and a focus electrode 4 corresponding to these plane parts 31 and 33 are shown.
The flat portions 31 and 33 are bent and inclined so that the distance between the flat portions 41 and 43 becomes larger toward each end of the flat portions 31 and 33.

In the electron gun configured as described above, the electron beams a ₁ and a ₃ on both sides are bent inward due to the asymmetry between the second grid electrode 3 and the focus electrode 4 with respect to the electron beams a ₁ and a ₃ . try to On the other hand, due to the inclination of the flat parts 31 and 33 having the electron beam passage holes 301 and 303 of the second grid electrode 3, the electron beams a ₁ and a ₂ tend to be bent outward as well. Therefore, the amount of inward bending and the amount of outward bending cancel each other out, and the electron beams a ₁ , a ₃
are electron beam passing holes 30 as shown in the figure.
1,303 center lines b ₁ and b ₃ . This ensures that the electron beams a 1 to a 3 pass through the center of the subsequent electron lens, and the electron beams a ₁ to _{a 3} reach the fluorescent surface without distortion, improving resolution.

As explained above, the present invention provides a color picture tube with excellent resolution because the distortion of the electron beams on both sides is suppressed by tilting the flat portions on both sides of the second grid electrode with respect to the opposing surfaces of the focus electrode. can be obtained.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing a conventional example, and Figure 2 is a vertical cross-sectional view of a conventional example.
FIG. 3 is a longitudinal sectional view showing an embodiment of the present invention. 3... Second grid electrode, 4... Focus electrode,
31, 33, 41, 43...plane part, 301, 3
02, 303, 401, 402, 403...electron beam passing hole, a ₁ , a ₂ , a ₃ ... electron beam, M...
...Electron gun. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A second grid electrode constituting a part of an in-line three-electron beam electron gun, and an electron beam passing hole corresponding to each of the three electron beam passing holes formed in the second grid electrode; a focus electrode disposed opposite to the grid electrode at a predetermined interval, and a mutual spacing between a plane portion having electron beam passing holes on both sides of the second grid electrode and a corresponding plane portion of the focus electrode; 1. A color picture tube characterized in that said plane part is bent and inclined so that said plane part becomes larger toward an end of said plane part.