JPH01248436A - Electron gun structure for color picture tube - Google Patents

Abstract

PURPOSE:To prevent damage of an electrode surface in contact with a spacer when it is to be drawn off, by jointing flanges together and fixing. CONSTITUTION:Flanges 5b, 5b of cylindrical electrodes 5a, 5b are jointed together and fixed without jointing together and fixing the cylindrical electrode parts 5a, 5b directly. Between these cylindrical electrodes 5, 6, therefore, a gap (g) can be provided for absorbing their elongation when they elongate in the axial direction due to heating and expansion at the time of heating and softening of a multi-form glass 9. This gap (g) absorbs and removes the pressure to spacers 51, 52 due to contraction generated at the time of cooling of the multi-form glass 9. This eliminates fear of damaging the contact surfaces of the spacers 51, 52 when they are drawn off.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improved structure of an electron gun assembly for a color picture tube.
In particular, the present invention relates to an improved assembly structure of an electron gun assembly having a pair of cylindrical electrodes formed by stacking two cylindrical electrodes.

[Conventional technology]

In a conventional electron gun assembly for a color picture tube, for example, as seen in Japanese Patent Laid-Open No. 60-163335, at least two cup-shaped electrode parts are stacked and the stacked parts are elastically biased in a direction away from each other. However, the assembly structure was such that the spaced portions were welded together using a laser.

FIG. 4 shows an example of a conventional pi-potential focusing type in-line electron gun, in which (a) is a central cross-sectional view on the long side of the electrode, and (b) is a central cross-sectional view on the short side of the electrode. In the figure, IA, IB, and IC are cathodes that emit electron beams A, B, and C from their top surfaces, respectively; 2 is a control electrode for controlling the beam current of electron beams A-C; and 3 is a control electrode for electron beam A. -C is an accelerating electrode for accelerating the electron beam A-C, and 4 is a focusing electrode for focusing the electron beam A-C, which is constructed by stacking a lower focusing electrode 5 and an upper focusing electrode 6 and bonding and fixing them. 7 is an anode.

The control electrode 2. The accelerating electrode 3 and the lower focusing electrode 5 are provided with electron beam passing holes 2A to 2C138 to 3G and 5A to 5C, respectively, and the upper focusing electrode 6 and the anode 7 are each provided with three aperture holes on their bottom surfaces. 6A to 6C and 7A to 7C are provided opposite each other, thereby 3
Three main lenses are formed corresponding to the electron beams A to C of the book.

Typical operating voltages for the electron gun are OV for the control electrode 2, 700 V for the accelerating electrode 3, and about 7 V for the focusing electrode 4.

In an electron gun configured such that 700 V is applied to the acceleration @ 43, about 7 KV to the focusing electrode 4, and 25 KV to the anode 7, three cathodes I
Each of the doublet beams is controlled by the signal potential applied to A to IC, and the three electron beams A to C are converged to one point by a predetermined means.

FIG. 5 is a top view of the focusing electrode 4 taken along the line PP in FIG. 4. The electron gun has multiform glasses 9 disposed above and below that insulate and support each component 2 to 7, and is housed in a cylindrical neck tube (not shown), so that the cylindrical portion 6a of the upper focusing electrode 6 of the focusing electrode 4 It has an elliptical shape with its major axis extending in the direction in which the three holes 6A to 6G are arranged, and the overlapping end of the flange portion 6b is inserted into the heat-softened multiform glass 9 and fixed. FIG. 6 shows a perspective view of the focusing electrode 4.
0A and 50B indicate fixing locations when the upper and lower cylindrical electrodes 6, 5 are bonded and fixed in advance by laser welding or the like. In other words,
Conventionally, the cylindrical portions 6a and 5a of the cylindrical electrodes 6 and 5 were directly joined and fixed.

[Problem to be solved by the invention]

Figure 4 shows the state immediately after the multiform glass 9 is welded and fixed, and the spacers 51, 52, and 53
are arranged in order to maintain the spacing between the electrodes and the coaxial precision of each horizontal hole to a predetermined precision. To fix the electrode, first, the multiform glass 9 is heated to a temperature above its softening point (1000 to 1300°C), and the electrode flange portion 5b is fixed.

6b and cooled in this state. In this case, the multiform glass 9 is heated and stretched in the longitudinal direction.
The Li pole flange portions 5b and 6b are embedded and fixed. The multiform glass 9 in which the flange portions 5b and 6b are embedded is rapidly cooled. When cooled, the multiform glass 9 shrinks and hardens, and the electrodes press against the spacers 51 and 52 from the axial direction. In this state, spacer 5
When the spacers 51 and 52 are pulled out, scratches are formed on the electrode surface that the spacers 51 and 52 are in contact with, and when the electron gun is in operation, this scratch causes sparks or light emission to occur, deteriorating the withstand voltage characteristics of the electrode. This had serious drawbacks in terms of reliability, such as a large current flowing between them and causing the power supply to generate heat.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved assembly structure which prevents scratching of the electrode surface in contact with the above-mentioned spacer when it is pulled out.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an assembly structure in which at least two or more cylindrical electrodes are joined and fixed together, in which the flange parts are joined and fixed together without directly joining the cylindrical electrode parts. It is characterized by

[Effect]

By joining and fixing the flange parts of the cylindrical electrode parts together without directly joining and fixing them together, when the cylindrical electrode heats and expands and extends in the axial direction when the multiform glass 9 is heated and softened, , a gap can be provided between the cylindrical electrodes to absorb the elongation. Since this gap absorbs and removes the pressing force on the spacer due to contraction that occurs when the multiform glass 9 is cooled, no scratches are left on the contact surface when the spacer is pulled out.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The focusing electrode 4 is composed of a lower focusing electrode 5 and an upper focusing electrode 6 as in the conventional case, and has similar flange portions 5b and 6, respectively.
b is provided.

When the multiform glass 9 is heated to a temperature above its softening point, the flange portions 5b and 6b are embedded in its width.
FIG. 2 shows the state immediately after embedding. Since the multiform glass 9 comes into contact with the flange portions 5b and 6b, it is rapidly cooled and begins to harden. On the other hand, the focused current t44 receives heat from the multiform glass 9 and expands. Flange part 5
Since both ends of b and 6b are fixed by the hardened multiform glass 9, the amount of elongation due to thermal expansion is as shown in FIG. deforms in the vertical direction, creating a gap g between the flange parts.

Next, when it is cooled, the gap g tries to return to its original state, and the gap returns to g=Q. As a result, a gap of g/2 remains between the upper focusing electrode 6 and the anode 7, and a gap of g/2 remains between the lower focusing electrode 5 and the accelerating electrode 3. As a result, the spacers 52, 53 will come out without resistance.

By setting the joint fixing points 50G of the upper and lower focusing electrodes on the flanges 5b and 6b in this way, the spacer 5
The removal force of 1.52 is reduced, no scratches remain on the contact surface with the spacers 51 and 52, and a highly reliable electron gun assembly is obtained.

According to experiments, it has been confirmed that g = 0, 02 to 0, 03 mm can be obtained by setting the 8th dimension (distance from the substrate of the flange portion to the bonding fixing point 50C) in Fig. 1 to 2fl11.

FIG. 3 shows another embodiment of the present invention, in which flange portions 5b, 6
Change the width shape of the base of b in a stepped manner.

6G of the step part (recession dimension b from the base of the flange part
) is provided with a welding fixing point 50D, but this also provides the same effect as above.

Note that although the above explanation is limited to the focusing electrode, it goes without saying that the same effect is obtained not only with this but also with the accelerating electrode.

〔Effect of the invention〕

As described above, in the cylindrical electrode that has a flange portion and this flange portion is embedded and fixed in multiform glass, the electrode The force required to remove the spacer to ensure dimensions can be reduced, and as a result, scratches on the electrode surface are reduced, resulting in a highly reliable color picture tube.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an assembled structure of a focusing electrode according to the present invention, FIG. 2 is a cross-sectional view of main parts showing an assembled state of an electron gun when using a focusing electrode according to the present invention, and FIG. 3 is a perspective view showing an assembled structure of a focusing electrode according to the present invention. FIG. 4 is a perspective view of a focusing electrode showing another embodiment, and FIG. 4 shows a schematic structure of a conventional in-line electron gun. FIG. Figure 5 is the same as Figure 4 (
FIG. 6 is a perspective view of a conventional focusing electrode, and FIG. 7 is a cross-sectional view of essential parts showing the assembly structure of a conventional electron gun. 4... Focusing electrode, 5... Lower focusing electrode, 6... Upper focusing electrode, 5a, 6a... Cylindrical electrode part, 5b, 6b
...Flange part, 50C:, 50D...4...-Focusing electrode 7...Anode 51, 52...Spacer 9...Multiform glass 6A to 6C...Electron beam passing hole 5b, 6b・・・Noranda part 50A, SOB...t・Bottom electrode bonding and fixing position Fig. 6

Claims (1)

[Claims] 1. An electron gun for a color picture tube having a pair of cylindrical electrodes formed by stacking at least two cylindrical electrodes each having a flange portion, joining and fixing the two, and embedding and fixing the flange portion in an insulator. An electron gun assembly for a color picture tube, characterized in that the flange portion is provided with a joining and fixing point for the cylindrical electrodes.