JPS6020864B2 - Color picture tube device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a color picture tube equipped with an in-line electron gun that emits three electron beams in one horizontal plane, and a horizontal deflection magnetic field with a pincushion-like distribution and a barrel-shaped Regarding a color picture tube device comprising a deflection yoke attached to the color picture tube to provide a distributed vertical deflection magnetic field, the aperture of the control grid electrode of the electron gun is approximately elliptical with its long axis in the vertical axis direction. In addition to reducing deflection aberrations, the shielding grid electrode (second grating) has a rectangular or elliptical bulge that bulges toward the control grid electrode, and is formed by the bulge. The dimensions of the working space are made smaller in the horizontal axis direction than in the vertical axis direction, eliminating the risk of aberrations caused by electric field distortion in the electron beam with an elliptical cross section that passes through the crossover section and reaches the crab light screen. It is something that

In a color picture tube equipped with an in-line electron gun, by distorting the horizontal deflection magnetic field distribution into a pincushion shape and the vertical deflection magnetic field distribution into a barrel shape, a so-called self-comparison configuration is achieved, which eliminates the need for a dynamic composition circuit. There are advantages that can be achieved.

However, each of the three electron beams passing through horizontal and vertical deflection magnetic fields distorted into a pincushion and barrel shape is distorted in its cross-sectional shape by the deflection magnetic field, and appears on the crab light screen surface. The resulting beam spot (
As schematically shown in FIG. 1, the shape of the bright spot is distorted into an ellipse, especially at the periphery of the screen surface.

As shown in Fig. 2, the deflection force exerted on the electron beam a with a perfect circular cross section by the horizontal deflection magnetic field A with a pincushion distribution is greater on the opposite side than on the tube side, and therefore expands significantly in the horizontal direction as the horizontal deflection angle increases.

In addition, the deflection force received by the vertical deflection magnetic field B with a barrel-like distribution is larger on the tube axis side than on the anti-tube axis side, and therefore, as the vertical deflection angle increases, its cross-sectional shape narrows in the vertical direction and expands in the horizontal direction. Therefore, at the corners of the screen, there is a large expansion in the diagonal direction. However, such distortion in the cross-sectional shape of the beam, that is, deflection aberration, is significant in wide-angle deflection type tubes, and is greatest at the periphery of the screen surface. In the color picture tube device of the present invention, the aperture of the control grid electrode is formed into a thin, almost elliptical shape with the long axis in the vertical axis direction, so that the electron beam, which is not subjected to deflection, is directed vertically onto the phosphor screen surface. The long wisteria is placed in an oval shape.

Therefore, by appropriately selecting the ratio of the major axis to the minor axis of the ellipse of the aperture, a nearly perfect circular beam spot is generated near the middle between the center and the periphery of the screen, as shown schematically in Figure 3. Do it like this. In this case, the beam spot generated at the center and periphery of the screen has an elliptical shape, but its fan flatness is smaller than that of the conventional one, and the deflection aberration over the entire screen area is improved. In the electrode arrangement of the in-line electron gun shown in FIG. 4, if the shape of the aperture 2 of the control grid electrode 1 is approximately elliptical in the vertical axis direction of the crab light screen 3, then
The electron beam passing through the crossover section 5 between the control grid electrode 1 and the blocking grid electrode (second grid) 4 has an elliptical cross-sectional shape.

However, the electron beam after passing through the crossover part 5 apparently diverges, and in the above-mentioned elliptical aperture, the divergence angle Qo is larger in the horizontal axis direction than in the vertical axis direction. In the lens section, especially in the main lens 6, beam aberration in the horizontal direction becomes large.

7 is a cathode arranged on a straight line in the horizontal direction, 8 is a prefocus lens, 9 is a first anode (third grating), and 10 is a second anode (fourth grating). In view of the above points, in the device of the present invention, as shown in FIGS. 5 and 6, the shielding grid electrode 4 has a rectangular or elliptical bulge that bulges toward the control grid electric machine 1 side. 11, and the bulge 1
The relationship hx<hy is established between the horizontal direction of the working space 12 formed by the working space 1 and the vertical direction diameter hy.

With this foundation, the curvature of the focusing field generated in the action space 12 is larger in the horizontal direction than in the vertical axis direction, and the beam focusing effect by the prefocus lens 8 is on the vertical axis. It is larger in the horizontal axis direction than in the horizontal axis direction, and it is possible to suppress the distortion caused by the difference in the divergence angle, that is, the occurrence of aberration due to electric field distortion.

As described above, according to the color picture tube device of the present invention, in particular, the aperture of the control grid electrode of the in-line electron gun has a substantially elliptical shape with its long axis perpendicular to the vertical axis direction, and the shielding grid electrode (second The grid) is provided with a rectangular or elliptical bulging portion that bulges toward the control grid electrode side, and the size of the working space formed by the bulging portion is adjusted in the horizontal axis direction compared to the vertical axis direction. The shape of the beam spot on the crab light screen is made vertically elliptical at the center of the screen, and the beam spot is horizontally elliptical at the periphery on the horizontal and vertical axes of the screen. This feature makes it possible to improve deflection aberrations over the entire screen surface.

Brief explanation of the drawings Figure 1 is a plan view schematically showing the shape of the beam spot on the screen surface of a conventional color picture tube device, and Figure 2 is a plan view schematically showing the shape of the beam spot on the screen surface of a conventional color picture tube device.
The figures are diagrams for explaining the generation of beam aberration due to self-comparison magnetic fields, Figure 3 is a plan view schematically showing the beam spot shape on the screen surface of a color picture tube device embodying the present invention, and Figure 4 1 is a schematic diagram showing a general electrode arrangement of an in-line electron gun, and FIGS. 5 and 6 are a sectional view and a perspective view of essential parts of an embodiment of a color picture tube device of the present invention.

1... Rare 9 grid electrode, 2... Aperture of the same electrode, 3... Crab light screen, 4...
Shielding grid electrode, 5...Crossover section, 6...Main lens, 8...Prefocus lens, 9...First anode,
10...Second anode, 11...Bulging part, 12
...A space of action.

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A color picture tube equipped with an in-line electron gun that emits three electron beams in one horizontal plane, and a color picture tube equipped with the color picture tube to provide the electron beam with a horizontal deflection magnetic field having a pincushion-like distribution and a vertical deflection magnetic field having a barrel-like distribution. In a color picture tube device comprising a deflection yoke attached to a picture tube, the aperture of the control grid electrode of the electron gun is approximately elliptical with its long axis in the vertical axis direction, and the control grid electrode is attached to the shielding grid electrode. having a rectangular or elliptical bulge that bulges out toward the side, and making the size of the working space formed by the bulge smaller in the horizontal axis direction than in the vertical axis direction; A color characterized in that the beam spot shape on the phosphor screen surface is a vertically elongated ellipse at the center of the screen, and a horizontally elongated ellipse at the periphery on the horizontal and vertical axes of the screen. Picture tube device.