JPS5845137B2 - Denshijiyuusouchi - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electron gun device 1.

FIG. 1 shows an example of a conventional electron gun device, in which reference numerals 1, 2, and 3 indicate an electron gun composed of a plurality of electrodes.

The electron guns 1, 2, and 3 are arranged to form an equilateral triangle at intervals of 120 degrees, and the axes of these three electron guns are arranged in such a way that their extension corresponds to one corner of the center of the screen. Each electrode is tilted by approximately 1 degree so as to form an equilateral triangular pyramid that intersects at one point on the surface of the shadow mask 4, which is the screening electrode.

The electron beams emitted from each of the electron guns 1.degree. 2.3 pass through the shadow mask 4 and strike the fluorescent surface 5, forming a desired image.

However, according to the above-mentioned conventional electron gun device, in order to achieve high resolution image quality, the axial length of each electron gun 1, 2.3 is made long and the tube diameter is made thick; 1. The cathode side of 2 and 3 (X side in Figure 1) is each electron gun 1,
2.3 comes close to or comes into contact with the inner wall of the glass housing the glass, which has the disadvantage of causing stray and sparks in this area.

Therefore, the image receiving characteristics of the color picture tube deteriorate.

Further, in order to eliminate this drawback, another idea as shown in FIG. 2 has been made.

In FIG. 1, 6, 7.8 are unipotential type electron guns, which are arranged in parallel to form an equilateral triangle with an interval of 120 degrees.

The opposing surfaces of the third grid electrode 10, fourth grid viewing pole 11, and anode electrode 12 of the electron guns 6, 7.8 have a certain inclination with respect to the axis as shown in FIG. It is configured so that it has

Therefore, with such a configuration, the electron gun 6°7.8
Electron beams a and b are emitted from the cathode of.

C passes through the inclined Nariko lens L (see Fig. 3) formed by the electrodes 10, 11, and 12, is bent at this portion, and then passes through the hole of the shadow mask 4 to a predetermined position on the fluorescent surface 5. To hit a fluorescent dot].

Therefore, according to this conventional idea, since the electron guns are arranged in parallel, the problems such as stray and sparks can be solved and the tube diameter of the electron gun can be made thicker, but the following problems arise. will occur.

That is, 3rd. The electron beam l incident in a circular shape on the main lens of the fourth grid electrode 10.11 and the anode electrode 12 is incident on the main lens 1. If the center is reversed, it will become an elliptical beam m whose long axis is in the direction in which the electron beam is bent from the central axis of the electron gun (see Figure 3C), and in this shape it will strike once on the fluorescent surface. .

This is because (1) the main lens L has a certain inclination with respect to the tube axis, so the electron beam incident on the main lens L1 is not uniformly focused, causing distortion in the cross section of the electron beam.

This is called astigmatism.

Therefore, conventional electron gun devices have the drawback of not being able to obtain good images and of significantly lowering the resolution.

The present invention aims to eliminate such drawbacks and will be explained in detail below using practical examples.

FIG. 4 shows a practical example of the electron gun device according to the present invention, and in this application, the cross section of the fourth grid electrode 11 in the electron gun device installation shown in FIG. 3 is made elliptical as shown in FIG. It is.

More specifically, the ellipse of the electron beam that strikes the cross section of the fourth grid pole 11 on the fluorescent surface (see Fig. 3 cm)
It is formed as an ellipse having a long axis in a direction perpendicular to the long axis.

Figure 5 a1 shows an example of an actual flame in which the electron gun in Figure 4 is applied to one electron gun device with a delta configuration, and Figure 5 shows a sectional view taken along the line X-X.
It is shown in the figure.

Cathode 13. The first grid is pole 14. 2nd grid'
The cross-sectional shape of the electron beam formed by the polarization change 15 and the third grid electrode 10 is a perfect circle, but the electron beam formed by the third grid electrode 10a, the fourth grid electrode 11a, and the fifth grid electrode 12a is tilted. When an electron beam enters the lens region, (1) A measure that occurs from the diagonal angle around 1 on the electrode opposing surfaces. Since the electron beam is inclined with respect to the axis, a force acts such that the cross-sectional shape of the electron beam becomes an ellipse having the long axis in the OA force direction in FIG.

(2) Force caused by ovalization of the focusing electrode cross section The cross section of the fourth grid electrode 11a is an ellipse with a long axis in the direction DEf perpendicular to OA, as shown in FIG. , is the same as the diameter of the 5-grid electrode, but its short axis is smaller than the diameter of the 3.5-grid electrode, so the 3.4.5-grid electrode area (here, the force acting on the electron beam as a whole) is greater than the OA force direction lens force.

Therefore, a force acts on the cross-sectional shape of the electron beam so as to rub it into an ellipse 1 having its long axis in the direction perpendicular to OA-.

The electron beam receives two forces:

Here, the force (1) acting on the cross-sectional shape of the electron beam and the force (2)
) are in the canceling direction, so the force in (1) and (
2) It is possible to balance the forces.

That is, by making the cross section of the fourth grid electrode 11a elliptical and adjusting the voltage applied to the electrode so that the best focus can be obtained at the center of the phosphor surface 5, the electron beam is made to strike the phosphor screen 5 as a perfectly circular beam spot. be able to.

As a result, the image formed on the phosphor screen can have high resolution and high quality.

Here, although the electron gun device explained in this example is an A-type electron gun device, the present invention is not limited to this, and can be applied to an in-line type electron gun device. Of course.

In this case, the electron gun located in the center is shown in Figure 3b (
However, there is no security in forming the main lens L, and there is also no security in forming the electrode 11 in an elliptical shape.

Further, in this embodiment, although the electron gun is a unipotential type electron gun having a main lens composed of a plurality of electron lenses, the present invention is not limited to this, and the electron gun of the Of course, the present invention can also be applied to an electron gun having a main lens system composed of lenses.

As explained above (according to the electron gun device according to the present invention), the electron beam can be projected onto the screen in a good shape, and each electron gun can be arranged in parallel, so the reliability of the device itself is improved. It will improve and provide better image quality.

[Brief Description of the Drawings] Figures 1, 2, and 3 are simplified groove diagrams showing an example of a conventional electron gun device, and Figures 4 and 5 are one embodiment of an electron gun device according to the present invention. FIG. 2 is a simplified configuration diagram showing an example. 1-3, 6-8...electron gun, 4...shadow mask, 5...fluorescent surface, 10...
...Third grid electrode, 11... Fourth grid electrode, 12... Anode electrode.

Claims (1)

[Claims] 1 at least a cathode and a first grid electrode, respectively;
consisting of an electron gun having a second grid electrode, a third grid electrode, a fourth grid electrode and a fifth grid electrode, and whose central axis is arranged substantially parallel to the tube axis f of the cathode ray tube;
In addition, by tilting the opposing surfaces of the electrodes of the main lens section consisting of the electrodes after the third grid electrode of each electron gun with respect to the central axis of the electron gun, each electron beam emitted from each electron gun is directed to a fluorescent surface. In an electron gun device in which the electron beam is focused on one point on the top, in order to correct astigmatism caused by the inclination of the electrode facing surface, the cross-sectional shape of the fourth grid electrode is adjusted by the main lens section. is formed into an ellipse having a short axis in a direction bent from the central axis, and when the electrode voltage is adjusted so that each electron beam can obtain the best focus at the center of the fluorescent surface, a circular beam spot is formed. An electron gun device characterized by being designed to fire and collide.