JPS6320047Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color cathode ray tube electron gun assembly that generates a plurality of electron beams.

In the electron gun assembly currently used in color cathode ray tubes that can generate multiple electron beams, only the cathode is electrically independent, and the G1 electrode, G2 electrode, and electron lens forming electrode are installed in front of the cathode. have a common structure both structurally and electrically. In such a color cathode ray tube, the video signal is superimposed on each cathode along with the DC component, and a
A DC voltage for controlling the cathode radiation current is commonly applied to the G1 and G2 electrodes and to the plurality of electron beams. Furthermore, in this type of color cathode ray tube, the DC component of the cathode is usually set to a cutoff voltage. It is desirable that the variation in this cut-off voltage between multiple cathodes is as small as possible due to drive characteristics, but this cut-off voltage is
It is determined by the structure of the triode section, which is made up of G2 electrodes. The distance between the cathode and the G1 electrode is b, the thickness of the G1 electrode is t, the distance between the G1 electrode and the G2 electrode is f, and the G1 electrode potential
If Ec1, G2 electrode potential Ec2, and G1 electrode hole diameter are D,
There is a relationship of Ec1∝D ³ /b×t×f×Ec2. In other words, the cut-off voltage is determined by the structure of the triode section.
It depends on D ³ /b×t×f. Normally, the G1 electrode-cathode spacing b is set after manufacturing the electron gun assembly.
Although it is set to an amount commensurate with the distance f between the G1 electrode and the G2 electrode, the amount of f is determined at the time of manufacturing the electron gun assembly. Furthermore, in the case of a color cathode ray tube that generates a plurality of electron beams, variations in f in the same electron gun appear as variations in cut-off voltage.

An object of the present invention is to provide an electron gun assembly that minimizes the above-mentioned variation in f.

In other words, a protruding surface is provided in which the central part of the bottom surface of the G2 electrode, which includes the electron beam passing holes of the dish-shaped G2 electrode, protrudes toward the G3 electrode side, and a surface including each electron beam passing hole within the protruding surface is provided. The G2 electrode surface facing the G1 electrode is reinforced by making the local part of the G1 electrode bulge toward the G1 electrode side.

To further explain the present invention to aid understanding, FIG. 1 is a schematic cross-sectional view of a conventionally used color cathode ray tube electron gun equipped with an integrated electrode. The electron beam emitted from the cathode 11
The amount of electron beam is controlled and accelerated by the G1 electrode 12 and the G2 electrode 13, and the prefocus lens formed between the G2 electrode 13 and the G3 electrode 14 performs preliminary focusing. A lens forms an image on a phosphor screen located in front of the electron gun. When manufacturing the electron gun structure, G1 electrode - G2
The electrode spacing, G2 electrode-G3 electrode spacing, and G3-G4 electrode spacing are determined using spacers with a predetermined thickness.
Set by positioning each electrode. Each electrode is fixed using two bead glasses 16 heated and melted.
is applied with a constant pressure from the left and right directions so as to sandwich the electron gun electrode assembly, and the bead glass 16 is welded to the electrode supports formed on each electrode of each electron gun electrode assembly. After cooling and solidifying, the spacer is pulled out.

Conventionally, as the G2 electrode 13, as shown in FIG. 2, the vicinity of the glass embedded part 13E is bent at a right angle, and a linear protrusion 13 is formed on the surface including the electron beam passage hole.
F has been provided and electrodes having a surface-reinforced shape have been used.

However, when using such a G2 electrode 13,
Due to the pressure exerted by the molten bead glass 16 and the stress and strain remaining after rapidly cooling the bead glass, the distance between the center of the G2 electrode and the G1 electrode is changed at right angles to the longitudinal direction of the pair of bead glasses, as shown in FIG. However, there was a drawback that the distance was narrower than the distance between the G2 electrode periphery and the G1 electrode.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is a perspective view of a G2 electrode 30 based on an embodiment of the present invention, and FIG. 5 shows a G2 electrode 30 including one electron beam passing hole in a direction perpendicular to the arrangement direction of a plurality of electron beam passing holes. A cross-sectional view is shown. The G2 electrode 30 is
It is a shallow dish-shaped electrode with a bottom surface 34 facing the G1 electrode and an outer edge 36 at the open end, a glass embedded part 31, and an integrated electrode including a plurality of electron beam passage holes. Furthermore, the center portion of the bottom surface 34 including the three electron beam passage holes is maintained in the same plane.
A bulging portion 33 that protrudes toward the G3 electrode side as a protruding surface 32 and bulges from the protruding surface 32 toward the G1 electrode side.
A, 33B, 33C are provided, and the bulging part 3
At the tip of 3, there are electron beam passing holes 35A, 35
B, 35C are drilled on the plane 36B-36B'.

When using the above-described G2 electrode 30, if the protruding surface 32 is made wide enough to withstand the pressure and stress strain of the molten bead glass 16 during manufacture of the electron gun, it can be used to include the electron beam passage hole. The strength of the surface and the surface facing the G1 electrode excluding the protrusion is dramatically improved, and it becomes possible to almost eliminate the electrode deformation (FIG. 4) seen in the conventional G2 electrode 13.

In addition, when the conventional G2 electrode 13 is used, the spacer for setting the gap between the G2 electrode and the G3 electrode used when manufacturing the electron gun is a linear protrusion used for reinforcing the surface including the electron beam passage hole of the G2 electrode. shape embankment 13
F must be avoided when using it, and if the linear protrusion 13F is made wider to further strengthen the reinforcement, the surface that the spacer for spacing setting will substantially come into contact with will be reduced, resulting in poor spacing setting accuracy. However, if the G2 electrode 30 as shown in the present invention is used, the spacer can be brought into contact with the protruding surface 32, so that the contact surface of the spacer can be made wider and larger. Thereby, it is possible to improve the interval setting accuracy.

As explained above, the present invention provides a protruding surface in the direction of the G3 electrode around the G2 electrode electron beam passage hole,
Furthermore, by expanding an area narrower than the protruding surface including the electron beam passage hole toward the G1 electrode,
Minimizes electrode deformation caused by the stress and strain left after quenching and the pressure applied to the molten bead glass during electron gun manufacturing, and maintains multiple electron beam passage holes within a common plane with high precision. have an effect.

Although the above description has been made regarding an in-line cathode ray tube electron gun assembly in which a plurality of electron beam passing holes are arranged in a straight line, the specific configuration of the present invention is not limited to the above-mentioned embodiments. In the case of delta type electron guns with multiple electron beam passage holes arranged in a delta arrangement, and various other types of electron guns,
Needless to say, it is applicable.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a conventionally used color cathode ray tube electron gun, FIG. 2 is a perspective view of the G2 electrode used in the color cathode ray tube electron gun shown in FIG. 1, and FIG. FIG. 4 is a perspective view of the G2 electrode according to an embodiment of the present invention, and FIG. The diagram includes the electron beam passage hole of the G2 electrode shown in Figure 4,
FIG. 3 is a cross-sectional view taken in a direction perpendicular to the direction in which a plurality of electron beam passing holes are arranged. 10... Conventionally used electron gun for color cathode ray tube, 13... Conventionally used G2 electrode,
32...Protruding surface, 33...Bulging part, 35...Electron beam passage hole, 13F...Linear protruding bank for reinforcing G2 electrode surface,
12...G1 electrode.

Claims (1)

[Scope of utility model registration request] In a dish-shaped G2 electrode whose bottom face faces the G1 electrode and has a plurality of electron beam passage holes formed in the same plane, the central part of the bottom surface including the electron beam passage holes is made to protrude toward the G3 electrode side. A cathode ray tube electron gun electrode structure comprising a G2 electrode which has a convex surface and has a local part of the surface including each electron beam passage hole bulged toward the G1 electrode side within the convex surface.