KR930008122Y1 - In-line type electron gun for cathode-ray tube - Google Patents

Abstract

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Description

Inline electron gun for cathode ray tube

1A and 1B are a plan view and a sectional view taken along line A-A showing a conventional cup-shaped main lens structure.

2A, 2B, and C are plan views showing the structure of a conventional conical electric field focus electrode, and B-B and C-C cross-sectional views.

3 is a cross-sectional view of an electron gun having a conventional conical field focus electrode.

4 is an equipotential diagram formed from a conventional conical field focus electrode.

Figure 5 is a cross-sectional view showing an equipotential line for explaining the electrode structure and operation according to the present invention.

FIG. 6 is a sectional view seen in the direction A of FIG.

7a, b is a perspective view of a plate-like electrode element and a cup-shaped electrode element according to the present invention.

* Explanation of symbols for main parts of the drawings

41: G ₃ electrode 42: G ₄ electrode

43, 45: plate type electrode element 44, 46: cup type electrode element

48a, 48b: overlap portion 49a, 49b: cup-shaped electrode body

50a, 50b: upper surface portions R, G, and B: electron beam through holes

The present invention relates to an inline electron gun for a cathode ray tube, and to an improved type of inline electron gun for a cathode ray tube in which the mechanical strength of the electrode is improved and the focus characteristic is improved.

In general, inline type electron gun for the cathode ray tube, the focus characteristic is influenced by the main lens, and the main lens diameter should be as large as possible to obtain good focus characteristics, but the main lens diameter is the electron gun structure of the cathode ray tube and the net accommodating the electron gun. It is limited by the diameter of the tube, and the main lens diameter of the electron gun sphere of the inline cathode ray tube is limited to about 30% of the neck diameter.

As is known, in the conventional inline type cathode ray tube electron gun, the first to fourth electrodes are sequentially arranged in front of several cathodes, and the fourth electrode has a structure fixed to the shield cup.

One embodiment of the cup main lens electrode of the conventional electron gun sphere is a cylindrical central electron beam through hole 3G and both sides in the upper surface portion 2 of the cup main lens electrode 1, as shown in Figs. Electron beam through holes 3R and 3B are provided, and the bent portion 4 of the upper surface portion 2 is integrated with the flange 6 via the side edge portion 5. The flange 6 is connected to the shield cup when the electrode 1 is the fourth electrode and is connected to the bottom electrode when the third electrode is used.

In addition, U-shaped bent portions 7 and 7 'are formed between the cylindrical electron beam passing holes 3R, 3G and 3B, and the bent portions 7 and 7' are formed at the center of the electrostatic lens and both outer sides thereof. The height h ₀ of the U-shaped bent portions 7, 7 ′ is generally about 1/3 or more of the aperture D ₀ of the electron beam through-holes so that the electrostatic lenses formed on the surface do not interfere with each other. It is known to be preferred.

Recently, the neck diameter is reduced to reduce the deflection power of the cathode ray tube, and thus the main lens diameter of the electron gun is naturally reduced, thereby deteriorating the focus characteristic. As a high resolution cathode ray tube is desired, a good focus characteristic of an electron gun is further demanded.

In order to improve the focus characteristic of the electron gun, many methods have been proposed, and among them, for example, a conical field focus (aka CFF) electrode such as a second degree has been proposed.

This conical focus electrode structure is an improvement of the cup-shaped electrode described above, and its configuration will be described with reference to FIGS. 2A, B, and C. In the upper surface portion 12 of the main lens electrode 11, the center having a diameter D _{1 is used} . The electron beam passing holes 13G and both electron beam passing holes 13R and 13B are drilled to form overlap regions 13RG and 13GB, respectively, between the through holes 13R, 13G, 13G, and 13B.

In addition, an electron beam through hole 14R, 14G, 14B having a diameter D ₂ is formed at a position separated by H from the upper surface portion 12, and a burring portion 15 having a length h is formed around the upper surface portion 12. Inclined portions 16 and V-shaped protrusions 17 and 17 'are formed from the electron beam through holes 13R, 13G, and 13B to (14R, 14G, 14B) of 12). The V-shaped protrusions 17 and 17 'and the burring 16 have an effect of reducing mutual interference between the electrostatic lens formed at the center and the electrostatic lens formed at both sides.

3 is a cross-sectional view of a bipotential (BPF) electron gun using an electric cone focusing electrode described above, in which a glass support 25 is provided in order of three cathodes 20R, 20G, and 20B and G _{1 to} G ₄ electrodes 21 to 24. FIG. It is fixed at. Here, the G ₃ electrode 23 and the G ₄ electrode 24 use the above-described conical electric field focusing electrode, and the upper surface portions of the two electrodes 23 and 24 are opposed to each other and fixed.

As shown by the equipotential lines shown in FIG. 4, such an electrode has an enlarged lens action of the electron beam through holes R, G, and B, and thus, the focus characteristics of the electrode are superior to those of the conventional cup-type electron gun electrode of FIG. .

However, in the method using the latter conical field focus electrode, there are many problems in the component strength characteristics and manufacturing cost of the main lens electrode.

For example, in the problem of component strength characteristics, the inclined surface 16 is formed from the opposing upper surface portion 12 to the burring portion 15, and the V-shaped protrusions 17 and 17 'are formed in the overlap region, and the length is also increased. When the burring portion 15, which is h ₁ , is formed, the mechanical strength decreases due to the shape of the complicated electron beam through hole. In particular, in the electron gun assembly process, the electrode is easily deformed, so that it is difficult to obtain a good constant resolution. In order to focus on the beam, the centers of both the outer electron beam through holes of the G ₃ electrodes 23 and the centers of the G ₄ electrodes 24 must be offset. Inadequate

Distance to the center of a more specifically to a second assist as G ₄ electrode day when passing the electron beam in the both outer sides from the center of the electron beam through hole (13G, 14G) of the center ball (13R, 14R, 13B, 14B ) (S) Is slightly larger than the spacing of the G ₃ electrode, and in view of the difference in the beam spacing, the conventional G ₄ electrode has a diameter D ₁ and a burring portion 15 of the conical portion 16 of the central electron beam passing hole. Since the outer sides are slightly larger than the diameter D ₃ of), when the G ₃ and G ₄ electrodes face each other, the beam spacing is slightly offset.

In the conventional electron gun, the positive converging characteristics are obtained by using the conical electric field focus electrode as described above, but the positive combo is possible because the shape of the electron beam through-hole is complicated and the manufacturing cost increases and the accuracy of the above-described offset cannot be maintained during electrode assembly. There was a defect that the synergistic characteristics were poor.

The subject innovation is to form a one that, G ₃ electrodes and G ₄ electrode combines waveform electrode elements formed on the ball plate-shaped cone beam passes through the cup-shaped electrode elements formed on the ball cup-shaped body the cylindrical electron beam passage made in view of solving the conventional various problems As a result, the mechanical strength of the electrode is increased and the thickness of the plate-shaped electrode elements of the G ₃ electrode and the G ₄ electrode is adjusted to improve the focus characteristics of the electrode. 7 to be described in detail as follows.

5 and 6, the G ₄ electrode 42 and the G ₃ electrode 41 are opposed to each other by a distance f, and the G ₃ electrode 41 has a plate-shaped electrode element having a thickness t ₁ ( 43) and the cup-shaped electrode element 44 are welded and assembled, and the G ₄ electrode 42 is welded and assembled by the plate-shaped electrode element 45 and the cup-shaped electrode element 46 having a thickness t ₂ .

The thickness t ₁ , t ₂ of each of the plate electrode element 43 and the plate electrode element 45 is maintained in a relationship of t ₂ <t ₁ .

As shown in FIG. 7B, the plate-shaped electrode elements 43 and 45 have conical electron beam through holes R, G, and B formed in the plate bodies 47a and 47b, and the through holes G in the center and both sides thereof. Overlap portions 48a and 48b are formed between the electron beam through holes R and B so as to overlap each other.

The plate-shaped electrode elements 43 and 45 have the same shape, and their thicknesses are made different from t ₁ and t ₂ , respectively.

As shown in FIG. 7A, the cup-shaped electrode elements 44 and 46 have cylindrical electron beam passing holes R, G, and B formed in the upper surface portions 50a and 50b of the cup-shaped electrode bodies 49a and 49b. It is the same as and is common in the present invention.

In general, when assembling the electron gun, each electrode is arranged in the assembly jig at predetermined intervals, and then heat is applied to the glass support to apply pressure in the direction of the tube axis, and the electrodes are fused to the glass support. Will receive.

That is, the stress at the time of arranging an electrode in an assembly jig, the compression stress at the time of fusion | melting on a glass support body, etc. are these.

The stress causes the electrode to be more stressed than the state before assembly, and thus deforms the shape of the electrode, causing a change in focus.

However, according to the electrode structure of the present invention, the plate-shaped electrode elements 43 and 45 and the cup-type electrode elements 44 and 46 for forming a conical electric field are separated and the mechanical strength thereof is much higher than that of the conventional cloud type electric field focus electrode CFF. The increase in focus hardly causes a change in focus.

In the present invention, as shown in FIG. 5, in the vicinity of both outer electron beam through holes R and B, the thickness t ₁ of the plate-shaped electrode element 43 for forming a conical electric field in the G ₃ electrode 41 is opposed. The infiltration of dislocations becomes shallower than the vicinity of the center electron beam through-hole G. As a result, both electron beams 52 and 53 pass through the equipotential lines 54. Bent inward toward 51).

But this time, G ₄ electrode 42, the thickness of the plate-shaped electrode element 45 for the electric field formed even if the same as that of G ₃ electrode 41 side and bent inward in the G ₃ electrode 41 on both sides of the electron beam (52, 53) The same equipotential line 55 meets the divergence effect in the inward direction due to the diverging action of the G ₄ electrode 42, but in the present invention, the plate-shaped electrode of the G ₃ electrode 41 and the G ₄ electrode 42 The thicknesses t ₁ and t ₂ of the elements 43 and 45 are set to t ₁ > t ₂ so that the equipotential lines 55 on the G ₄ electrode 42 side are larger than the equipotential lines 54 on the G ₃ electrode 41 side. Since the inclination is gentle, the beam focusing action on the side of the G ₃ electrode 41 becomes stronger so that the paths of the electron beams 51 and 52 on both sides are (51 ', 52') so that the main lens electrodes 41 and 42 of the present invention can be Positive convergence is obtained.

As described above, the present invention can be manufactured by separating the conical electric field forming electrode and the cup-shaped electrode, and the manufacturing is simple, and the conical electric field forming electrode is a plate having a predetermined thickness. Fluctuation can be eliminated, and if the thickness of the plate-shaped electrode element for conical electric field forming the G ₃ electrode and the G ₄ electrode is appropriately selected, there is an advantage in that good positive convergence characteristics can be obtained.

Claims (1)

The G ₃ electrode 41 and the G ₄ electrode 42 of an inline electron gun sphere for a cathode ray tube focusing three electron beams on a fluorescent surface are composed of a conical electric field through hole and a cylindrical electron beam through hole, and the conical field electron beam The through hole is a cup-shaped electrode element constituting the G ₃ electrode 41 and the G ₄ electrode 42 in which an overlap part is formed by overlapping each other with the center through hole G and the through holes R and B on both sides thereof. 44, 46) the cup-shaped electrode bodies (49a, 49b) of the upper surface portion (50a, 50b) passing through the cone the electron beam formed in the electron beam passing ball coaxially with the ball (R, G, B) to have each of the thickness t ₁ of, _{t 2 (t 2 <t 1} ) of plate material (47a, 47b) of the plate-shaped electrode element in-line type electron gun for cathode-ray tubes characterized in that hayeoseo combining (43, 45) with.