JPS6145344B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron gun device suitable for application to various cathode ray tubes including color television picture tubes.

In order to improve the sharpness of the image in a television receiver, it is possible to modulate, for example, the horizontal scanning speed of the electron beam on the fluorescent surface of the picture tube, thereby modulating the substantial amount of light emitted by the fluorescent surface. It will be done. In this manner, in order to modulate the beam scanning speed, the electron beam is deflected, for example, in the horizontal scanning direction using the modulation signal, thereby substantially modulating the beam scanning speed. Such beam deflection can be achieved by various methods, for example, as shown in _FIG . In an electron gun device in which a third grid G ₂ (accelerating electrode), a third grid G ₃ (first anode electrode), a fourth grid G ₄ (focusing electrode), and a fifth grid G ₅ (second anode electrode) are arranged in sequence, The fourth grid _G4 is divided into two parts with respect to the axis 0 direction of the electron gun.
Some are composed of _{G 4a} and G _4b . These electrode parts G _4a and G _4b are, as shown in FIG.
Each of them is made into a cylindrical shape, and the mutually opposing end surfaces maintain a uniform interval in each part, and each of these end surfaces obliquely intersects the axis 0 in a horizontal plane including the axis 0, and a vertical plane including the axis 0. , it is made perpendicular to the axis 0. In such a configuration, each electrode portion G _4a and G _4b of the fourth grid G ₄ has a third
The grid G ₃ and the fifth grid G ₅ work together to provide a fixed low voltage for constructing a unipotential main electron lens, and also to provide both electrode portions G _4a
A scanning velocity modulation signal in the horizontal direction of the beam is applied between G4a and _G4b , and the horizontal direction (direction along the plane of the paper in FIG. 1) is applied by the inclined end surfaces of both electrode parts _G4a and _G4b
A potential gradient corresponding to a modulation signal is applied to the electron beam, the electron beam is deflected in the horizontal direction, and the scanning speed in the horizontal direction is modulated.

However, when using such a method, the machining operation for forming the inclined end faces on the electrode portions G _4a and G _4b is relatively troublesome, and the machining operation for forming the inclined end faces on the electrode portions G _4a and G _4b is relatively troublesome.
The disadvantage is that it is relatively difficult to assemble the slanted end faces of each part while maintaining the required spacing.

In addition, in such a configuration, the distance l that receives the horizontal electrostatic deflection of the electron beam is, in other words, the range where a horizontal potential gradient occurs between the two electrode parts G _4a and G _4b . This is the direct projection length between G _4a and G _4b on the axis 0 of the slit. On the other hand, each electrode part _4a and _4b needs to have a certain length of the cylindrical part whose inclined end surface is not cut in order to maintain its _mechanical strength. In an electron gun whose length is shortened, the effective length l may become insufficient to receive the electrostatic deflection.

As another deflection method, for example _, as _shown in _FIG . It is divided into two parts along the vertical plane along 0, each having a semi-cylindrical shape, and consists of two electrode parts _G4a and _G4b having a cylindrical shape as a whole, and as explained in FIGS. 1 and 2. Similarly, both electrode parts G _4a
A modulation signal is applied between the electrode portions G _4a and G 4b, and a potential gradient in the horizontal direction is applied between the electrode portions G _4a and G _4b in accordance with the modulation signal, thereby deflecting the beam. In this case, for example, as shown in FIG. 4, the electrode parts G _4a and G _4b are bent radially outward from both side edges of the vertically divided semi-cylindrical electrode parts G _4a and G _4b . Each pair of protrusions (1) are integrally provided, and their outer ends are embedded in the beading glass 2 to which the other electrodes are respectively fixed, so that the positional relationship between the electrode parts G _4a and G _4b can be determined. It is used to set not only the settings but also the positional relationship with other electrodes.

However, when using such vertically divided semi-cylindrical electrode portions G _4a and G _4b , these electrode portions G _4a
When G _4b is fixed, if an external force is applied to it in the radial direction, especially in the vertical direction, it will be deformed, the roundness will be impaired, and the electric field will be distorted. That is, in this electron gun, the main electron lens system is formed by the cooperation of the fourth grid G ₄ and the third and fifth grids G ₃ and G ₅ in the preceding and subsequent stages. Grid G ₄ , 3rd and 5th Grid G ₃ and
Due to the low roundness of the end facing G ₅ and the slit formed between both electrode portions G _4a and G _4b , this fourth grid G ₄ is connected to the third and fifth grids. Distortion occurs in the electric field formed between G ₃ and G ₅ , resulting in distortion in the main electron lens.

The present invention aims to provide an electron gun device that eliminates the above-mentioned drawbacks.

An example of the present invention will be described with reference to FIGS. 5 to 8. In this example as well, the first to fifth grids G ₁ to G ₅ are sequentially arranged on the same axis 0 with respect to the cathode K, and a unipotential type main grid is arranged between the third to fifth grids G ₃ to _{G 5} . This is the case in which an electrostatic deflection electric field is desired to be obtained in the fourth grid _G4 to which a low voltage is applied in an electron gun forming an electron lens.

In the present invention, the fourth grid _G4 , which is intended to form a deflection electric field, is composed of two electrode parts _G4A and _G4B , and these electrode parts _G4A and _G4B are arranged as shown in FIG. As shown in FIG. 2, it is composed of cylindrical caps 11A and 11B made of metal, and wall portions 12A and 12B that are approximately semi-cylindrical.

The cylindrical caps 11A and 11B have cylindrical portions 13A and 13B, respectively, and end plates 14A and 14B provided at their outer ends, as shown in a partially cutaway view of FIG. , end plate 14
Center holes 15A and 15B are bored in A and 14B. In the illustrated example, inner cylindrical portions 16A and 16B are provided around the center holes 15A and 15B and protrude concentrically into the cylindrical portions 13A and 13B. Caps 11A and 11B having such a structure are manufactured by press molding.

The wall portions 12A and 12B each form a vertically divided substantially semi-cylindrical shape, and have reinforcing ribs 17A protruding outward at corresponding positions on both ends, that is, on substantially the same circumference.
18A, 18B, and 17B are formed. These cylindrical wall portions 12A and 12B can be manufactured by press working.

Then, both semi-cylindrical wall portions 12A and 12B are electrically and mechanically attached to each one of the caps 11A and 11B, respectively. This attachment is performed between the cylindrical parts 13A and 16A of each cap 11A and 11B.
Wall parts 12A and 12B between 13B and 16B respectively
One end of each of the caps having ribs 17A and 17B is inserted so that the cylindrical center axes of these wall portions 12A and 12B and the center axes of both caps 11A and 11B coincide, and at the tops of the ribs 17A and 17B, Each of the caps 11A and 11B and the wall portions 12A and 12B are spot welded at several locations.

In this way, the electrode parts G 4A and G 4B, which are formed by integrating the caps 11A and 11B and the wall parts 12A and 12B, respectively, are connected to the third electrode parts _G4A and _G4B , as shown in FIG.
Both caps 11A and 11B are arranged on the axis 0 between grid _G3 and fifth grid _G5 , and between both caps 11A and 11B, both cylindrical wall portions 12A and 12B are on the same cylindrical surface without contacting each other. , and both wall surfaces 12A and 1
The gap between caps 11A and 11B is arranged such that each wall section 12A and 12B extends between each cap 11A and 11B, respectively, along a vertical plane. and,
Each cap 11 of both cylindrical wall portions 12A and 12B
The ends opposite to the ends attached to A and 11B are connected between the cylindrical parts 13B and 16B of the other caps 11B and 11A, and between 13A and 16B, respectively.
The caps are inserted between the caps 11B and 11A so as not to come into contact with them. Therefore,
Each cap 1 of each cylindrical wall surface part 12A and 12B
The ribs 18A and 18B at the end opposite to the side to be welded to 1A and 11B are set lower in height than the ribs 17A and 17B on the welded side.

In the above configuration, in order to form a unipotential main electron lens in both electrode portions G _4A and G _4B of the fourth grid G ₄ and between this and the third grid G ₃ and the fifth grid G ₅ . While applying the required common fixed voltage to both electrode parts G _4A and G _4B
For example, a horizontal scanning velocity modulation signal voltage is applied between them.
In this way, in response to this modulation signal voltage, the potential gradient in the direction intersecting the axis 0, in the above example, the potential gradient between the electrode parts G _4A and G _4B , especially between the semi-cylindrical wall parts 12A and 12B, the axis 0 in the above example. Since a horizontal potential gradient is generated perpendicular to the modulation signal, the electron beam emitted from the cathode K and passing through the fourth grid _G4 is electrostatically deflected, and the scanning speed is modulated. Become.

As described above, also in the configuration of the present invention, for example, the fourth grid _G4 is connected to the two electrode parts _G4A and _G4B.
However, in the configuration of the present invention, an electric field is formed between the longitudinally divided cylindrical wall portions 12A and 12B, so that the electron beam is effectively deflected. major l fourth
The distance can span almost the entire length of the grid _G4 , and even if the length of the fourth grid _G4 is shortened, its effective length l can be made sufficiently large.

According to the present invention, both electrode portions G _4A and G
Although _4B has a vertically divided structure, its third grid _G3 and fifth grid
By arranging cylindrical caps at both ends facing G ₅ , wall portions 12A and 12B
It is possible to avoid disturbances in the electric field of the main electron lens due to the slit in between, and the roundness of the main lens is guaranteed by the caps 11A and 11B, so that the slit formed by the wall portions 12A and 12B is The roundness of the circle can be made looser, and both wall surfaces 1
2A and 12B are reinforced by caps 11A and 11B to mechanically hold the cylindrical shape, so both electrode parts _G4A and _G4B can be attached to the beading glass via pins etc. although not shown in the figure. Even when fixing, it is possible to avoid loss of roundness, and thereby avoid distortion in the main electron lens.

Further, according to the above-described configuration of the present invention, both caps 11A and 11B, cylindrical wall portions 12A and 12B
Since it can be manufactured entirely by press molding, it can be mass-produced.

The example shown in FIG. 5 is a case where the present invention is applied to a single beam single electron gun, but it can also be applied to various electron guns including a double beam single electron gun in which a common grid is provided for a plurality of cathodes. It can be applied to In addition, in the above example, the electrode that obtains the potential gradient in the direction perpendicular to the axis 0 is the low voltage side electrode that constitutes the unipotential main electron lens. This can be applied when the electrode is a low-voltage side electrode of a bipotential type main electron lens, another electrode, or an electrode of another type of electron gun.

In addition, in the above example, a potential gradient for deflecting the electron lens in a horizontal direction perpendicular to the axis 0 may be obtained, but this method can be used to obtain a potential gradient in other directions intersecting the axis 0. The invention can also be applied.

Further, in the example described above, two semi-cylindrical wall portions 12
A and 12B are used to obtain an electric field for deflecting an electron beam, but it is not limited to the two wall parts, nor is it limited to the electric field for deflecting the electron beam. It can be applied to correction of beam spot shape by four wall sections arranged in a polar configuration. An example of this case is shown in FIG. In Figure 9, the fifth
Portions corresponding to the figures to FIG. 8 are given the same reference numerals and redundant explanations are omitted, but in this case, four cylindrical wall portions 12A ₁ vertically divided along the axis 0,
12A ₂ , 12B ₁ , 12B ₂ maintain equal angular intervals so that they form one cylindrical surface, and every other wall surface portion 12A ₁ and 12A ₂ in the horizontal and vertical directions are 12B ₁ and 12B ₂ . are arranged to face each other, the mutually opposing wall parts 12A ₁ and 12A ₂ are electrically and mechanically connected to one cap 11A, and the other mutually facing wall parts 12B ₁ and 1 are electrically and mechanically connected to one cap 11A.
_2B2 is electrically and mechanically connected to the other cap 11B to form a pair of electrode portions _G4A and _G4B .

[Brief explanation of the drawing]

1 and 3 are sectional views of conventional electron guns, FIGS. 2 and 4 are perspective views of essential parts, FIG. 5 is a sectional view of an example of an electron gun device according to the present invention, and FIG. 6 is a sectional view of a conventional electron gun. 7 is a partially cutaway perspective view of the cap, FIG. 8 is a perspective view of the cylindrical wall, and FIG. 9 is a part of another example of the device of the present invention. FIG. K is a cathode, _G1 to _G5 are first to fifth grids, _G4A and _G4B are electrode parts, 11A and 11B are their cylindrical caps, 12A, 12B, 12
A ₁ , 12A ₂ , 12B ₁ , and 12B ₂ are cylindrical wall portions, respectively.

Claims (1)

[Claims] 1. In an electron gun device equipped with an electrode that generates a potential gradient in a direction intersecting the axis, the electrode consists of a pair of electrode parts, and the pair of electrode parts includes a pair of cylindrical caps arranged coaxially. , the cylindrical caps have cylindrical wall portions that collectively form a cylinder centered on the axes of the two caps, each extending toward the other cap along the axes of the caps. The caps are electrically and mechanically attached, and each of the caps is provided with an end plate portion, and a circular hole is formed in the center of each end plate portion, and a required signal voltage is applied between the two electrode portions. An electron gun device characterized in that a potential gradient is generated between the cylindrical wall surface portions of both electrode portions.