JPS61296646A - Shadow mask type color cathode-ray tube - Google Patents

Abstract

PURPOSE:To get good landing for obtaining the improvement in multiple color tolerance by making the blue, green and red colored phosphor dot configurations formed on a screen consistent with the blue - red colored electron beam configurations at the four coners of the screen. CONSTITUTION:Phosphor dot configurations are arranged like polygonal line so as to set them to the displacement of electron beam configurations, so that minimum value of multiple color tolerance T, which is the distance of phosphor dot peripheral neighboring the peripheral edge of electron beam, becomes larger. Therefore, minimum multiple color tolerance can be improved, for example at the corner part of primary quadrant, by making the tilt angle gamma of the line connecting phosphor dot MR to MG with respect to X axis larger than the tilt angle beta of the line connecting phosphor dot MB to MG with respect to X axis.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shadow mask type color cathode ray tube equipped with an in-line electron gun, and in particular, the present invention relates to a shadow mask type color cathode ray tube equipped with an in-line electron gun. This invention relates to a high-resolution color cathode ray tube in which the image quality is uniformly distributed.

[Conventional technology]

As previously known, shadow mask type color cathode rays! Regarding It, the through holes of the shadow mask are roughly divided into round holes and rectangular holes, and the arrangement of electron guns is roughly divided into delta type and inline type.

Now, regarding high resolution color cathode ray tubes, from the viewpoint of resolution, the overwhelming majority of the holes in the shadow mask are round holes, and the electron gun arrangement is often in the form of a delta.

However, recently, in-line type electron guns have been increasingly used for high-resolution color cathode ray tubes to simplify adjustment. (Hereinafter, this method will be referred to as the dot-in-line type.) In the conventional dot-in-line type color cathode ray tube, the third
(As shown in this figure, blue, green, and red phosphor dots MB, MG, to (
The dots are repeated in this order at regular intervals, and a set of blue, green, and red phosphor dots MB, MG, and MR are arranged at each vertex of a triangle, and the display surface is were arranged in the same pattern over the entire surface.

[Problem that the invention seeks to solve]

The in-line electron gun is centered around an electron gun that emits an electron beam (hereinafter referred to as green electron beam) BG that strikes a green phosphor dot MG that is placed on a perpendicular line passing through the center of the display screen. , electron guns that emit blue and red electron beams are installed on both sides of the X-axis, as shown in Figure 4.
At the center of the display surface (1), electron beams BB, BG, BR
are lined up on the X axis.

As shown in a partially enlarged view in circle A in FIG.
/2 on the straight line, at positions shifted by P/2, with an interval P
Therefore, the through holes (3) through which the electron beam passes are formed in a constant pattern over the entire surface, and this shadow mask (2) is formed in a spherical shape, and is in a constant pattern with the spherical display surface (1). They are mounted inside the color cathode ray tube so that they face each other with an interval of .

In the color cathode ray tube configured in this way, for reasons of rotation, the three color electron beams are arranged in the X
Tilt with respect to the axis. However, in actual color cathode ray tubes, there is not only a tilt due to this rotational reason (electron beams BB, BG).

This causes a displacement in which the BR deviates from the straight line.

Figures 6 (1) to (IV) are diagrams showing changes in the arrangement of electron beams BB, BG, and BR at the corners of the first to fourth quadrants, respectively, where the outer electron beams are each displaced toward the X axis. do. This means that each electron beam hits each color phosphor dot on the display surface (1) (hereinafter referred to as
This is called landing. ) is quite different for the three colors blue, green, and red. As a result, color shifts tend to occur at the four corners of the display surface (1) where landing is poor.
For this reason, it is necessary to improve the resolution by reducing the distance between the holes in the shadow mask and the distance between the phosphor dots, or to increase the brightness of the image by increasing the size of the holes and phosphor dots in the shadow mask. This was an obstacle to achieving this goal.

This invention was made to solve the above-mentioned problems, and the display screen (1)
The objective is to obtain a color cathode ray tube in which landing is as uniform as possible for both green and red colors.

[Means for solving problems]

This invention provides at least four corners of the display screen with phosphor dots of gastro-green-red colors, blue, green and red phosphor dots at the four corners.
They are arranged so as to correspond to the displacement of the red single beam arrangement.

[Effect]

The arrangement of the phosphor dots at the four corners of the display surface where the electron beam array is displaced is arranged in accordance with the displacement of the electron beam array, which improves the landing at the four corners of the display surface and improves the other color tolerance T. will improve.

[Embodiments of the invention]

An embodiment of this invention will be described below. FIG. 1 is a diagram showing the arrangement of the phosphor dots in the corner of the first quadrant of the display screen in an embodiment of the present invention and the positional relationship with the electron beam, and FIG. This is a diagram showing the arrangement of one unit, and the distance between the outer periphery of the 9-beam, the dot, and the outer periphery of the adjacent phosphor dot (hereinafter referred to as other color tolerance) is set so that the minimum value of T becomes large. , the fluorescent dots are arranged in a polygonal line in accordance with the displacement of the electron beam arrangement. For example, in the corner of the first quadrant, the inclination angle γ of the line connecting the phosphor dots M-MG with respect to the X axis is made larger than the inclination angle β of the line connecting the phosphor dots MB-MG with respect to X and FlII. For example, in a 20-inch color cathode ray tube, the pitch P of the holes (3) in the shadow mask (2) is 315 μm, the diameter of the fluorophore dots is 90 μm, the diameter of the electron beam is 160 μm, and the holes (3) in the shadow mask (2) are In 3), the inclination angle with respect to the X-axis is 3.70°, and the inclination angles with respect to the X-axis of the lines connecting electron beams BB-BG and BR-BG are 8.03° and 5.40°, respectively. The minimum other color tolerance T of a conventional color cathode ray tube in which the light dots MR, MG, and MR are arranged on a straight line with an inclination angle α of 4.20° with respect to the X axis is 36.0 μm. In contrast, as in this example, MB-MG.

When the inclination angles β and γ of the MR-MG are set to 8.03° and 5°40, respectively, the minimum other color tolerance T is 39.1 μm. This means that the minimum other color tolerance T has improved by 8.6%.

The above explanation concerns the corner portions of the first quadrant, but the arrangement of the electron beams in the corner portions of the second to fourth quadrants is similar to the Y-axis and the X-axis, respectively, as shown in FIG. Needless to say, since the phosphor dots are displaced symmetrically with respect to each other, the phosphor dots are also arranged in a polygonal line shape.

Note that the above explanation is about the four corners where the displacement of the electron beam array is the largest, but the electron beam array is
As shown in the figure, the X-axis and Y-axis are parallel to the X-axis, and the displacement is greatest at the four corners. Since the other color tolerance T is sufficiently large even with the conventional arrangement except for the four corners, it is necessary to match the arrangement of the phosphor dots to the displacement of the electron beam arrangement over the entire display surface (1). Instead, for example, only the four corners of the display surface may be formed with a constant polygonal line arrangement to match the state where the displacement of the electron beam arrangement is the largest.

〔Effect of the invention〕

As described above, according to the present invention, the array of blue, green, and red phosphor dots formed in a certain pattern on the display surface is arranged such that the blue, green, and red phosphor dots are arranged in a certain pattern on the display surface at least in the four corners of the display surface. Since the arrangement is made to match the displacement of the electron beam arrangement, ideal landings are given for each of the three colors blue, green, and red, and the minimum other color tolerance T can be increased. A color cathode ray tube with less color shift can be obtained, and along with this, it is possible to improve the resolution by reducing the distance between the holes in the shadow mask and the distance between the phosphor dots, or to improve the resolution by reducing the distance between the holes in the shadow mask and the distance between the phosphor dots. By increasing the size of the light dot, it is possible to improve the brightness of the image.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the positional relationship between the array of phosphor dots in the corners of the first quadrant of a fluorescent screen according to an embodiment of the present invention and the array of electron beams, and FIG. A partially enlarged view showing the arrangement of light dots. Figure 3 is a diagram showing the arrangement of a set of fluorescent dots on the fluorescent screen of a conventional color cathode ray tube. Figure 4 is a view from the fluorescent screen side. Figure 5 is a diagram showing the placement position of the electron gun and the arrangement relationship of the holes formed in the shadow mask. Figure 5 is a diagram showing the displacement of the array at the four corners of the electron beam. Figure 6 (1) - (IV) is an enlarged view showing the displacement of the electron beam arrangement at the corner portions of the first to fourth quadrants, respectively. MB... Blue phosphor dot, MG... Green phosphor dot, MR... Red phosphor dot, BB... Blue electron beam, BG... Green electron beam, BR. ...Red electron beam. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a shadow mask type color cathode ray tube in which blue, green, and red phosphor dots are formed in a fixed array pattern on the display surface and equipped with an in-line electron gun, at least four blue in the corner,
A shadow mask type color cathode ray tube characterized in that green and red phosphor dots are arranged so as to correspond to the displacement of the arrangement of blue, green and red electron beams at the four corners of the display surface.