JPH0360145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides an in-line type color picture tube;
The present invention relates to a color picture tube device comprising a drive means for the color picture tube device.

Conventional configuration and its problems In an in-line color picture tube in which three electron beam emitters are arranged horizontally in a straight line, a saddle-type or toroidal-type deflection yoke is used as the beam deflection means. Therefore, the horizontal deflection magnetic field distribution is distorted into a pink tension shape, and the vertical deflection magnetic field distribution is distorted into a barrel shape. In this way, a self-convergence effect can be obtained, and the configuration of the convergence system can be greatly simplified.

On the other hand, as shown in FIG. 1, the bright spots, or beam spots 2, that appear particularly in the peripheral area of the phosphor screen surface 1 are distorted non-circularly due to deflection distortion, and the resolution in the peripheral area of the phosphor screen surface 1 is reduced. descend. The beam spot 2 consists of a high-brightness core part 3 in the shape of an oblong ellipse and a low-brightness haze part 4 attached thereto.

This reduction in resolution due to deflection distortion can be alleviated by reducing the diameter of the electron beam that passes through the main lens of the electron gun and the deflection magnetic field. If the distance is narrowed or the beam is simply narrowed down strongly using a pre-focus lens, the lens magnification will become excessive, leading to the undesirable result that the beam spot appearing in the center of the phosphor screen becomes larger in diameter.

As shown in Figure 2, the optimal focus potential when considering the horizontal diameter of the beam spot remains unchanged at any position on the phosphor screen surface, while when considering the vertical diameter of the beam spot. The optimum focus voltage increases toward the periphery of the phosphor screen (especially in the E and NE directions). Therefore, if the beam spot is driven at the optimum focus voltage (6KV in Figure 2) that takes into account only the horizontal diameter of the beam spot, the beam spot that appears at the periphery of the phosphor screen becomes overfocused in the vertical direction, resulting in the above-mentioned problem. This produces a vertical haze like .

Therefore, as shown in Figure 3, if the vertical focus voltage at the center of the phosphor screen surface is lower than the horizontal optimum focus voltage, the resolution at the center of the phosphor screen surface will decrease slightly, but the resolution at the periphery will decrease slightly. Resolution can be increased.

OBJECTS OF THE INVENTION It is an object of the present invention to achieve high resolution across the entire phosphor screen surface without resorting to the aforementioned compromises, i.e. without sacrificing the resolution in the central part of the phosphor screen surface. An object of the present invention is to provide a color picture tube device that can obtain high image quality.

Structure of the Invention The color picture tube device of the present invention includes a first plate-like electrode in which three vertically long electron beam passing holes are arranged in parallel in the horizontal direction; A focusing electrode structure for generating a quadrupole lens electric field consisting of second plate-shaped electrodes arranged in parallel in the horizontal direction,
An in-line type in which a main lens is generated between a final acceleration electrode, which is disposed between a first focusing electrode and a second focusing electrode, and to which a constant high voltage is applied, and the second focusing electrode adjacent thereto. Equipped with a color picture tube. A constant first focus voltage is applied to the first plate-shaped electrode and the first focusing electrode, while the beam deflection angle is increased to the second plate-shaped electrode and the second focusing electrode. Accordingly, a second focus voltage that gradually increases from the first focus voltage is applied, and this will be described in detail below with reference to embodiments shown in the drawings.

Description of Examples In FIG. 4, 5 is a control electrode, 6 is an acceleration electrode, 7 is a first focusing electrode, 8 is a focusing electrode structure for generating a quadrupole lens electric field, 9 is a second focusing electrode, and 10 is a final acceleration Shows electrodes. The focusing electrode structure 8 is shown in FIG.
A first plate-shaped electrode 1 having a planar shape as shown in
1 and 11', and second plate-shaped electrodes 12 and 12' having a planar shape as shown in FIG.
The first plate-shaped electrodes 11, 11' have three vertically long electron beam passing holes 1 arranged in parallel in the horizontal direction.
3, 14, and 15. Further, the second plate-like electrodes 12, 12' have three horizontally long electron beam passing holes 16, 17, 1 arranged in parallel in the horizontal direction.
It has 8.

The first plate-shaped electrodes 11, 11' are connected to the first focusing electrode 7 within the tube, and a first focus voltage is applied thereto.
V _g3 is applied. Moreover, the second plate-shaped electrode 12,
12' is connected to the second focusing electrode 9 within the tube, and the second focus voltage V _g3 ' is applied to this, thereby causing the first plate-shaped electrodes 11, 11'
Three quadrupole lens electric fields as shown in FIG. 6 are generated between the second plate-shaped electrodes 12 and 12'.

When the quadrupole lens electric field is set to the relationship of V _g3 <V _g3 ', it acts as a converging lens in the horizontal direction,
In the vertical direction, it acts as a diverging lens. Therefore, if the first focus voltage V _g3 is kept constant and the second focus voltage V _g3 ' is gradually increased from V _g3 as the deflection angle increases, a quadrupole lens electric field as described above is generated, As the deflection angle increases, the electron beam passing through this area is subjected to the effects of convergence in the horizontal direction and divergence in the vertical direction.

On the other hand, since the high voltage applied to the final accelerating electrode 10 is constant, the final accelerating electrode voltage and the beam focusing effect of the main lens generated between the second focusing electrode 9 and the final accelerating electrode 10 and the second focusing electrode It will be weakened by decreasing the difference with the voltage. Therefore, in the horizontal direction, the beam focusing effect strengthened by the quadrupole lens electric field and the beam focusing effect weakened by the main lens cancel each other out, resulting in optimum focus. Furthermore, in the vertical direction, the beam diverging effect of the quadrupole lens electric field and the weakened beam focusing effect of the main lens combine to cause underfocus.

Therefore, even though the above-mentioned special perpendicular overfocusing effect is applied to the electron beam deflected by the deflection magnetic field of the in-line deflection yoke, the beam spot generated on the phosphor screen surface is , the diameter is reduced regardless of whether it is at the center or at the periphery on the same screen surface, and the diameter is close to a perfect circle.

To explain such an effect with reference to FIG. 7, a in the figure shows the cross-sectional shape of an electron beam that is in an optimal focused state both horizontally and vertically, and the electron beam strikes the center of the phosphor screen surface. . In the same figure, b shows the cross-sectional shape of an electron beam (ignoring the quadrupole lens electric field) that is focused by the main lens, whose focusing power is weakened as the deflection angle increases.
C in the same figure shows the cross-sectional shape of the electron beam subjected to the action of the quadrupole lens electric field. d in the figure shows the cross-sectional shape of the electron beam that passes through the quadrupole lens electric field, the main lens, and the deflection magnetic field and impinges on the peripheral portion of the phosphor screen surface.

In the embodiment described above, two first plate electrodes 1
1 and 11', two second plate electrodes 12,
However, following the first plate electrode 11, the second plate electrode 12, the first plate electrode 11', and the second plate electrode 12' are arranged in order.
The plate-shaped electrodes 11, 11' may be connected to the first focusing electrode 7, and the second plate-shaped electrodes 12, 12' may be connected to the second focusing electrode 9, respectively.

Further, in the above-described embodiment, each of the first and second plate-shaped electrodes is configured with two pieces, but either one or both may be configured with one piece or three or more pieces. Furthermore, the second focusing electrode side end surface 7a of the first focusing electrode 7 itself may be used as the above-mentioned first plate electrode.

Effects of the Invention Since the present invention is configured as described above, the beam spot is small in diameter and close to a perfect circle over the entire area of the phosphor screen surface, so high resolution can be obtained, and especially high-definition reproduced images can be obtained. It is suitable for the required color picture tube device and exhibits excellent effects.

[Brief explanation of drawings]

Figure 1 is a diagram to explain the shape distortion of the beam spot of an in-line color picture tube, Figure 2 is a characteristic diagram showing the relationship between the position of the shape distortion and the optimum focus voltage, and Figure 3 is a diagram for vertical focus. A focus voltage characteristic diagram when deflection distortion is reduced by lowering the voltage below its optimum value. FIG. 4 is a side view of an electron gun of a color picture tube device implementing the present invention.
5a and 5b are plan views of the first and second plate electrodes of the electron gun, FIG. 6 is a diagram showing the quadrupole lens electric field generated within the focusing electrode structure of the electron gun, and FIG. 7
Figures a, b, c, and d are cross-sectional diagrams of electron beams for explaining the operating principle of the apparatus of the present invention. 7... First focusing electrode, 8... Focusing electrode structure, 9
...Second focusing electrode, 10...Final accelerating electrode, 1
1, 11'...first plate electrode, 12, 12'...
Second plate electrode, 13, 14, 15, 16, 1
7, 18...Electron beam passage hole.

Claims (1)

[Claims] 1. A first plate-shaped electrode in which three vertically long electron beam passage holes are arranged in parallel in the horizontal direction, and a second plate-shaped electrode in which three horizontally long electron beam passage holes are arranged in parallel in the horizontal direction. A focusing electrode structure for generating a quadrupole lens electric field is disposed between the first focusing electrode and the second focusing electrode, and a final accelerating electrode to which a constant high voltage is applied, and An in-line color picture tube is provided which forms a main lens between two focusing electrodes, and a constant first focus voltage is applied to the first plate electrode and the first focusing electrode, while the second focusing electrode is As the beam deflection angle increases, the plate-like electrode and the second focusing electrode
A color picture tube device characterized in that a second focus voltage that gradually increases from the focus voltage is applied.