KR910001870B1 - Electron gun of color cathode ray tube - Google Patents

Abstract

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Description

Color gun tube gun

1 is a sectional view of the main part of an electron gun for color-brown tubes in one embodiment of the present invention;

2 and 3 are graphs showing the relationship between the distance between the grid electrode cylindrical portion of the electron gun and the field correction electrode, and the distance between the straight electron beam focusing point and the deflection electron beam focusing point in the embodiment of the present invention. ,

4 is a partially broken side view showing a conventional electron gun for color-brown tubes,

Fig. 5 is a side view showing the overall shape of a color brown tube electron gun in one embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

6, G5: the fifth grid electrode 6S _1, 6S _2, 6C: cylindrical portion

6A: the electric field correcting electrode 6A _S1, 6A _S2, 6Ac: electron beam passage hole

7: _S1 sixth grid electrode 7, 7 _s2, 7c: cylinder portion

7A, G6: Field correction electrode 7 _S1 , 7 _S2 , 7A _C : Electron non-pass hole

10: electron gun 10a: bead glass

12: Seal Cup

The present invention relates to an electrode structure of an electron lens forming electrode suitable for the improvement of focus characteristics, in particular an electron gun for inline type CRTs.

In the in-line electron gun, since the electron beams are arranged on one plane, the diameter of the main lens becomes smaller compared to the delta array type. Further, the smaller the diameter of the glass bulb neck is, the better the main lens diameter is, due to limitations in deflection power, large version, and the like, resulting in deterioration of focus characteristics. In addition, the gap between the outer diameter of the electron gun and the inner diameter of the neck also needs to be set to, for example, 1 mm or more in order to reduce the effects of undesirable electron radiation or the like, and there are many limitations in that the diameter of the main lens cannot be increased. Therefore, a multistage focused electron gun has been proposed as a means of improving the focus performance among many restrictions. This multi-stage focused electron gun can focus the electron beam gently, and improve the spherical aberration of the electron lens.

4 is a partially broken axial view of a typical multi-stage focused electron gun. In the same drawing, the electron gun includes the cathode 1, the first grid 2, the second grid 3, the third grid 4, the fourth grid 5, the fifth grid 6 and the sixth grid. It consists of (7). In addition, with the third grid 4, the fourth grid 5 and the fifth grid 6, one lens system is formed which contributes to directing each electron beam in parallel with each other toward the fluorescent surface, and the fifth grid 6 ) And another lens system contributing to focusing each of the electron beams parallel to the sixth grid 7 to the fluorescent surface (the actual focusing point is on the shadow mask, but for the sake of simplicity). The main lens has these lens systems. In addition, the third grid 4 and the fifth grid 6 are electrically connected to each other, and a focus voltage, for example, about 7 KV is applied, and the fourth grid 5 and the sixth grid 7 are electrically connected to each other. A positive voltage, for example, about 25 KV is applied, and the focus characteristic is drastically improved with the multi-stage focused electron gun having the bi-potential type and the glass potential type as a whole. In FIG. 4, 8 denotes bead glass.

In addition, the structure of the electron gun for color-brown tubes is described, for example in Unexamined-Japanese-Patent No. 57-63750. In addition, a patent application (Ser. No. 307,572) is also filed in the United States.

When the multi-stage connection type electron gun according to the above-described configuration is applied to, for example, a 22-inch type color tube tube, practically, sufficient focusing characteristics can be obtained. However, especially in recent years, it has become necessary to mass-produce a larger color CRT at 29 inches. However, in such a large CRT, the distance from the electron gun to the fluorescent surface is different from that until now. And the fifth and sixth grids having changed inclination angles of the end faces 6 'and 7' of the cylindrical portions on both sides of the sixth glove 7, and the specification of the new size is to be examined. Since it takes a long time to manufacture electrode parts, timely mass production cannot be started. That is, it is necessary to determine the inclination amounts of both cylindrical portions in the fifth grid and the sixth grid for each variety, and there is a problem that a very long period of time is required for production period, specification determination, and the like.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to share a cylindrical portion inclined to an existing cross section, to obtain a desired concentration angle, and to improve the fogger characteristics for each variety. To provide.

In order to achieve the above object, the electron gun for color-brown tubes of the present invention is provided with an electric field correction electrode in at least one existing grid electrode having a cylindrical portion inclined in one cross section.

The electron gun for color-brown tubes in this invention arrange | positions a preliminary correction electrode as mentioned above, an electron beam moves substantially parallel, and a concentration angle is controlled suitably.

As described above, the electron gun to which the present invention can be applied has a grid electrode having an inclined cross section of the cylindrical portion. Accordingly, the electron gun to which the present invention can be applied comprises a first electrode means for directing at least two electron beams along the initial passages parallel to each other toward the fluorescent surface, and a substantially separate main lens in the passages of the electron beams. Thereby, a second electrode means for focusing each of the above electron beams at a predetermined position on a predetermined surface such as a fluorescent surface is provided. For this reason, grid electrodes having an opening in which the electron beam passing pearl coincides with the central axis are arranged to face each other.

The preliminary correction electrode newly disposed in the electron gun of the present invention includes a cylindrical portion in a grid electrode having an opening in which a center axis coincides with the electron beam path, and a cylindrical portion whose one end surface is inclined with respect to the central axis. It is arrange | positioned facing a predetermined space | interval, and it is often arrange | positioned especially in the inclined cross section side of the cylindrical part. The field correction electrode is usually in the form of a flat plate, which is convenient to be orthogonal to the central axis, but is not limited thereto. Distance between the cylindrical portion of the grid electrode and the field correction electrode (11), (12) Near the focus point on a predetermined surface of the electron beam (usually the center electron beam) and the electron beam that is deflected in a straight line by experiment or calculation What is necessary is just to determine so that the distance (X) with respect to the focal point on the predetermined surface of (normally an outside electron beam) may be within a desired value, for example, within 1 mm. Although an appropriate positive voltage is applied to the field correction electrode, it is usually convenient to electrically connect the grid electrode. It goes without saying that the field compensation electrode also has a through hole for each electron beam.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described in detail using drawing.

FIG. 1 is a sectional view showing main parts of an embodiment of a color brown tube electron gun according to the present invention, and the same reference numerals are given to the same parts as the above drawings. In the same figure, the inside of the fifth grid electrode 6 has an electron beam coaxially with the outer cylindrical portions 6 _S1 , 6 _S2 and the central cylindrical portion 6 _C inclined in cross section. An electric field correction electrode 6A having passage holes 6A _S1, 6A _S2 , and 6Ac is disposed to face the cylindrical portion. Similarly, inside the sixth grid electrode 7, the outer cylindrical portions 7 _S1 (7 _S2 ) having both inclined cross sections and the central cylindrical portion 7C are coaxially arranged with each non-electromagnetic tube hole ( The field correction electrodes 7A each having 7A _S1 ) (7A _S2 ) and (7Ac) are arranged to face the cylindrical portion.

The center of each electron beam through hole coincided with the central axis of each corresponding cylindrical portion. In addition, the hole diameter was 5.5 mm, which was the same as the inner diameter of the cylindrical portion. In addition, the central shafts S of the central cylindrical portions 6C and 7C and the cylindrical portions 6 _S1 , 6 _S2 , and ( 7 _S1), the distance (Y) between the central axis of the (7 _S2) was set to 6.6mm. In addition, (nl) (n2) diameter of FIG. 1 was set to 3.1 mm and 2.8 mm, respectively.

In this embodiment, the plate-shaped field correction electrode 6A (or 7A) is provided near the central portion in the axial direction of the grid electrode 6 (or 7), but the present invention is not limited to this. As the material of the field correction electrode, a conventional CRT electrode material may be used, and it is convenient to use the same material as that of the grid electrode.

With such a configuration, the electron beam passages of the cylindrical portions 6 _S1 and 6 _S2 in which both sides of the fifth grid electrode 6 are inclined, the cylindrical portion 6C and the field correction electrode 6A are inclined. Since each of the electron lenses by the electric field is formed between the holes 6A _S1 , 6A _S2 , and 6Ac, the apparent inclination of the radio wave lens formed only by the fifth grid electrode 6 is corrected by this electron lens. Thus, the concentrated angle of the electron beam is controlled to be corrected. In addition, by arranging the field correction electrode 7A for the sixth grid 7, the apparent inclination of the electron lens is corrected as described above.

Therefore, the electron beam passing holes 6A _S1 , 6A _S2 , and 6Ac of the cylindrical portions 6 _S1 , 6 _S2 , 6c and the field compensation electrode 6A in the fifth grid electrode 6 are thus provided. the cylindrical portion (7, _S1), (7, _S2), (7c) and each of the electron beam passage hole (7A _S1) of the electric field correction electrode (7A) (7A in the axial direction distance 11 and the sixth grid electrode 7, _S2 ), when the axial distance with (7Ac) is set to (12), the distance at which the electron beam is concentrated in the direction of the central axis (X) (the electron beam shifted in the direction toward the central axis (5)) The focusing point and the distance between the center electron beam passage and the centerline of the hole) are in a straight line relationship with the value of (11) or (12) in the example of a 110-inch tube of 29 inches. And decreases with increasing value of (11) or (12). Therefore, by appropriately selecting the distances 11 and 12 in the axial direction, the desired electron beam concentration angle (for example, (X) is 1 mm or less) is obtained. For example, in the electron gun of this embodiment, if 12 is fixed at 3.2 mm, the relationship between (11) (mm) and (X) (mm) becomes as shown in FIG. In this example, (11) was set to 4.5 mm and (12) to 3.2 mm.

When (12) is fixed to an appropriate value, for example, 3.2 mm, and the right angle of the electron beam is corrected by (11), a good result can be obtained by setting the value of Normal (11) to 3 to 6 mm.

FIG. 5 shows the overall shape of the color-brown tube electron gun according to the present embodiment. As shown in FIG. 5, the electron gun 10 has a cathode (not shown) on the stem glass 11b provided with a step pin lla. K), first grid G1. A ratio in which the second grid G2, the third grid G3, the fourth grid G4, the fifth grid G5, the sixth grid G6, and the shield cup 12 are sequentially stacked to predetermined dimensions It is supported by the glass 10a, and is comprised. In the present embodiment, the fourth grid 5 and the sixth grid 7 are electrically connected, a positive voltage of 25 KV is applied, and the third grid 4 and the fifth grid 6 are electrically connected. A focus voltage of 33% of the anode voltage is applied.

The outer contours of the flat plates of the field correction electrodes 6A and 7A in this embodiment are almost the same as the outlines of the grid section cut by the field correction contour surface at the insertion portion thereof.

In addition, in the above-described embodiment, the case in which the field correction electrode is disposed in both of the fifth grid electrode 6 and the sixth grid electrode 7 has been described, but the present invention is not limited thereto, and at least the fifth grid is described. It may be disposed in the electrode 6. That is, in the case of disposing in the sixth grid electrode 7, the shield cup is disposed at the tip of the sixth grid electrode 7, i.e., the fluorescent surface, so that a large control of the concentration angle is not possible, but in the fifth grid electrode 6 By excretion, the concentration intensity can be greatly controlled, and most of the concentration angles can be determined. By simultaneously disposing in the sixth grid electrode 7, fine adjustment of the concentration angle is possible, and the desired electron beam concentration angle can be set. However, even if the field correction electrode is provided only in the sixth grid electrode 7, the effect is as it is. In addition, in the above-described embodiment, the case in which the electric field correction angle is used as the plate-shaped electrode has been described. However, the present invention is not limited thereto. Not to mention what you can get.

The electron gun of the present invention does not interfere with the conventional electron gun structure having a cylindrical section inclined at one end thereof except that the field correction electrode is disposed in the fifth grid or in the fifth grid and the sixth grid.

As described above, according to the present invention, the concentration angle of the electron beam can be controlled by disposing the electric field correction electrode in an existing grid electrode having a cylindrical portion having an inclined cross section. In combination with existing grid electrodes, it is possible to improve the focus characteristics and at the same time achieve extremely excellent effects such as the commonization of the electrodes for color-brown tubes of various sizes.

Claims (7)

A first electrode means for directing at least two electron beams along the initial paths parallel to each other toward the fluorescent surface, and a substantially separate main lens in the passages of the electron beams to focus each electron beam on a predetermined surface; A grid electrode having two electrode means and having an opening corresponding to the electron beam path and a central axis and spaced apart from each other, and at least one end of the cylindrical portion of the grid electrode in the second electrode means; An electron gun for a color brown tube inclined with respect to a central axis, comprising: i) disposing a field adjusting electrode in a grid electrode disposed on the opposite side to at least the fluorescent surface with a cylindrical portion inclined in the cross-section, and ii) on a predetermined surface of a straight electron beam. So that the distance X between the focusing point and the focusing point on the predetermined surface of the electron beam deflected in the advancing direction becomes a desired value, A color CRT electron gun, characterized in that the distance (11) (12) of the cylindrical portion and a group grid and the field-correction electrode of the electrode that is determined. The electron gun for color-brown tubes according to claim 1, wherein the field correction electrode is disposed on the inclined end surface side of the grid electrode. 2. The apparatus of claim 1, further comprising two or more grid electrodes having a cylindrical section having an inclined cross section, wherein a shield cup is disposed on a fluorescent surface side of the grid electrode on the most fluorescent surface side, and the field correction electrode is opposite to the fluorescent surface side. An electron gun for color-brown tubes disposed in one of said grid electrodes disposed in the grid electrode. The electron gun for color tube tubes according to claim 1, wherein the predetermined surface is a fluorescent surface. The electron gun for color-brown tubes according to claim 1, wherein the field correction electrode has a flat plate shape with an electron beam passing hole. The electron gun for color-brown tubes according to claim 6, wherein the flat outer contour of the field correction electrode has substantially the same cross section of the grid electrode at the insertion portion thereof. The electron gun for color-brown tubes according to claim 1, wherein the field correction electrode is electrically connected to a corresponding grid electrode.

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